Oil Prices and the Canadian Dollar: December 2015

This has been a difficult year for the Canadian dollar. Ever since oil prices started falling in mid 2014, the Canadian dollar has traded lower. Currently, in this low interest rate environment, oil prices seem to be the main driver of the Canadian dollar. From an international investment perspective, Canada is seen as consisting of safe banks and companies specializing in extracting natural resources. As a result, our currency and stock market both tend to follow commodity prices. Right now, commodity prices are depressed (especially oil) and this has taken the Canadian dollar down to lows not seen for over ten years.

Here are some plots of oil prices ($US per barrel, WTI) and how many US dollars one Canadian dollar buys. The monthly data are sourced from FRED. Notice the close correlation between the two data sets over the last half of the sample period.



As a starting point, I estimate a linear relationship between the two series.

The plot shows a positive correlation between oil prices and the exchange rate, but there seems to be some nonlinear behaviour towards the beginning and ending period of the data set.

Next, I estimate a quadratic fit. This doesn't look too different from the linear fit.


Perhaps a cubic fit is more appropriate. The cubic fit looks much better! Notice how the cubic curve fits the curvature at the beginning and ending period of the data.



Here are the model fits. The cubic curve fits the best.

	linear	quadratic	cubic
Adjusted R squared	0.6511	0.6507	0.6923
Sigma	0.0660	0.0660	0.0620

Here are some forecasts for each of the three regression models.

oil price	linear	quadratic	cubic
30.00	0.77	0.77	0.75
35.00	0.79	0.78	0.75
40.00	0.80	0.80	0.77
45.00	0.82	0.81	0.78
50.00	0.83	0.83	0.80
55.00	0.85	0.84	0.82
60.00	0.86	0.86	0.85
65.00	0.87	0.87	0.87

Today, oil is currently trading around $37 per barrel. An oil price of  $35 per barrel produces an exchange rate forecast of 75 cents (using the cubic model). The actual exchange rate at time of writing is 74 cents. Overall, a fairly close fit.


The R script and data set are posted below.
#########################################################
#  Economic forecasting and analysis
#  Perry Sadorsky
#  December 2015
#  Oil prices and the Canadian dollar
##########################################################


rm(list=ls())
# load libraries
library(fpp)


as2_data <- read.csv("C:/econ 6210/6210f15/assignment 2/as2_data.csv")
View(as2_data)


df = as2_data
df =  ts(df, start=1986, frequency=12)


plot(df[,-1], main="Oil prices and exchange rates", ylab = "", xlab = "")


oil = df[,"oil"]
fx = df[,"fx"]


# 5 year rolling correlations
rollout1 = rollapply(df[,-1], 60 ,function(x) cor(x[,1],x[,2]), by.column=FALSE,align="right")
rollout1 = na.omit(rollout1)
plot(rollout1,main="Rolling 5 year correlations between FX and Oil prices")


## linear fit
lm1 = lm(fx ~ oil)
summary(lm1)
str(summary(lm1))

rr = matrix(0,nrow=2, ncol=3)
rr[1,1] = summary(lm1)$adj.r.squared
rr[2,1] = summary(lm1)$sigma

par(mfrow=c(2,2))
plot(lm1)
par(mfrow=c(1,1))

plot(fx ~ oil, main="Linear fit",
     ylab="$US/$C", xlab="Oil prices ($/bbl)")
abline(lm1)

oil_f = c(30, 35, 40, 45, 50, 55, 60, 65)

fcast1 <- forecast(lm1, newdata=data.frame(oil=oil_f))
fcast1
plot(fcast1, ylab="$US/$C", xlab="Oil prices ($/bbl)")


## quadratic fit
lm2 = lm(fx ~ oil + I(oil^2))
summary(lm2)
rr[1,2] = summary(lm2)$adj.r.squared
rr[2,2] = summary(lm2)$sigma

par(mfrow=c(2,2))
plot(lm2)
par(mfrow=c(1,1))


plot(fx ~ oil, main="Quadratic fit",ylab="$US/$C", xlab="Oil prices ($/bbl)")
curve( coef(lm2)[1] +  coef(lm2)[2]*x +  coef(lm2)[3]*x^2 , add=T   )


fcast2 <- forecast(lm2, newdata=data.frame(oil=oil_f))
fcast2



## cubic fit
lm3 = lm(fx ~ oil +I(oil^2) +I(oil^3) )
summary(lm3)
rr[1,3] = summary(lm3)$adj.r.squared
rr[2,3] = summary(lm3)$sigma

par(mfrow=c(2,2))
plot(lm3)
par(mfrow=c(1,1))


plot(fx ~ oil, main="Cubic fit",ylab="$US/$C", xlab="Oil prices ($/bbl)")
curve( coef(lm3)[1] +  coef(lm3)[2]*x +  coef(lm3)[3]*x^2 +  coef(lm3)[4]*x^3, add=T  , col = "blue" )


fcast3 <- forecast(lm3, newdata=data.frame(oil=oil_f))
fcast3
fcast3$mean


tablef = cbind(oil_f, fcast1$mean, fcast2$mean, fcast3$mean)
colnames(tablef) = c("oil price", "linear", "quadratic", "cubic")
tablef

colnames(rr) = c("linear", "quadratic","cubic")
rownames(rr) = c("Adjusted R squared", "Sigma")
rr

date oil fx 1 1/1/1986 22.93 0.7107321 2 2/1/1986 15.46 0.7120986 3 3/1/1986 12.61 0.7138268 4 4/1/1986 12.84 0.7205130 5 5/1/1986 15.38 0.7269027 6 6/1/1986 13.43 0.7194762 7 7/1/1986 11.59 0.7242178 8 8/1/1986 15.10 0.7202017 9 9/1/1986 14.87 0.7208246 10 10/1/1986 14.90 0.7202017 11 11/1/1986 15.22 0.7213446 12 12/1/1986 16.11 0.7245852 13 1/1/1987 18.65 0.7349699 14 2/1/1987 17.75 0.7496252 15 3/1/1987 18.30 0.7579203 16 4/1/1987 18.68 0.7580352 17 5/1/1987 19.44 0.7456566 18 6/1/1987 20.07 0.7469934 19 7/1/1987 21.34 0.7540341 20 8/1/1987 20.31 0.7543754 21 9/1/1987 19.53 0.7602250 22 10/1/1987 19.86 0.7635336 23 11/1/1987 18.85 0.7594744 24 12/1/1987 17.28 0.7648184 25 1/1/1988 17.13 0.7779074 26 2/1/1988 16.80 0.7885192 27 3/1/1988 16.20 0.8005123 28 4/1/1988 17.86 0.8095200 29 5/1/1988 17.42 0.8082114 30 6/1/1988 16.53 0.8212878 31 7/1/1988 15.50 0.8281574 32 8/1/1988 15.52 0.8171938 33 9/1/1988 14.54 0.8151952 34 10/1/1988 13.77 0.8295313 35 11/1/1988 14.14 0.8206138 36 12/1/1988 16.38 0.8359806 37 1/1/1989 18.02 0.8394191 38 2/1/1989 17.94 0.8409722 39 3/1/1989 19.48 0.8365401 40 4/1/1989 21.07 0.8411844 41 5/1/1989 20.12 0.8385744 42 6/1/1989 20.05 0.8343067 43 7/1/1989 19.78 0.8409722 44 8/1/1989 18.58 0.8504848 45 9/1/1989 19.59 0.8454515 46 10/1/1989 20.10 0.8511363 47 11/1/1989 19.86 0.8549201 48 12/1/1989 21.10 0.8611039 49 1/1/1990 22.86 0.8532423 50 2/1/1990 22.11 0.8357710 51 3/1/1990 20.39 0.8474576 52 4/1/1990 18.43 0.8590327 53 5/1/1990 18.20 0.8512812 54 6/1/1990 16.70 0.8525149 55 7/1/1990 18.45 0.8643042 56 8/1/1990 27.31 0.8735150 57 9/1/1990 33.51 0.8633342 58 10/1/1990 36.04 0.8620690 59 11/1/1990 32.33 0.8594757 60 12/1/1990 27.28 0.8618461 61 1/1/1991 25.23 0.8650519 62 2/1/1991 20.48 0.8658758 63 3/1/1991 19.90 0.8641549 64 4/1/1991 20.83 0.8669267 65 5/1/1991 21.23 0.8696408 66 6/1/1991 20.19 0.8742023 67 7/1/1991 21.40 0.8700948 68 8/1/1991 21.69 0.8732099 69 9/1/1991 21.89 0.8795075 70 10/1/1991 23.23 0.8866034 71 11/1/1991 22.46 0.8847992 72 12/1/1991 19.50 0.8720677 73 1/1/1992 18.79 0.8642295 74 2/1/1992 19.01 0.8456660 75 3/1/1992 18.92 0.8383635 76 4/1/1992 20.23 0.8421762 77 5/1/1992 20.98 0.8339588 78 6/1/1992 22.39 0.8361204 79 7/1/1992 21.78 0.8386448 80 8/1/1992 21.34 0.8398421 81 9/1/1992 21.88 0.8179959 82 10/1/1992 21.69 0.8030194 83 11/1/1992 20.34 0.7890169 84 12/1/1992 19.41 0.7858546 85 1/1/1993 19.03 0.7825338 86 2/1/1993 20.09 0.7935248 87 3/1/1993 20.32 0.8018603 88 4/1/1993 20.25 0.7923302 89 5/1/1993 19.95 0.7875256 90 6/1/1993 19.09 0.7819220 91 7/1/1993 17.89 0.7800312 92 8/1/1993 18.01 0.7645260 93 9/1/1993 17.50 0.7567159 94 10/1/1993 18.15 0.7539772 95 11/1/1993 16.61 0.7590709 96 12/1/1993 14.52 0.7514277 97 1/1/1994 15.03 0.7591285 98 2/1/1994 14.78 0.7449344 99 3/1/1994 14.68 0.7329229 100 4/1/1994 16.42 0.7230658 101 5/1/1994 17.89 0.7242178 102 6/1/1994 19.06 0.7227522 103 7/1/1994 19.66 0.7232750 104 8/1/1994 18.38 0.7255315 105 9/1/1994 17.45 0.7385524 106 10/1/1994 17.72 0.7405762 107 11/1/1994 18.07 0.7327618 108 12/1/1994 17.16 0.7197869 109 1/1/1995 18.04 0.7076139 110 2/1/1995 18.57 0.7140307 111 3/1/1995 18.54 0.7103786 112 4/1/1995 19.90 0.7266386 113 5/1/1995 19.74 0.7348078 114 6/1/1995 18.45 0.7259528 115 7/1/1995 17.33 0.7346459 116 8/1/1995 18.02 0.7378985 117 9/1/1995 18.23 0.7402472 118 10/1/1995 17.43 0.7430525 119 11/1/1995 17.99 0.7388799 120 12/1/1995 19.03 0.7303002 121 1/1/1996 18.86 0.7315824 122 2/1/1996 19.09 0.7271670 123 3/1/1996 21.33 0.7322789 124 4/1/1996 23.50 0.7357269 125 5/1/1996 21.17 0.7303002 126 6/1/1996 20.42 0.7321716 127 7/1/1996 21.30 0.7300869 128 8/1/1996 21.90 0.7287567 129 9/1/1996 23.97 0.7302468 130 10/1/1996 24.88 0.7403020 131 11/1/1996 23.71 0.7473283 132 12/1/1996 25.23 0.7341066 133 1/1/1997 25.13 0.7410701 134 2/1/1997 22.18 0.7376807 135 3/1/1997 20.97 0.7285974 136 4/1/1997 19.70 0.7172572 137 5/1/1997 20.82 0.7244277 138 6/1/1997 19.26 0.7223868 139 7/1/1997 19.66 0.7259528 140 8/1/1997 19.95 0.7191658 141 9/1/1997 19.80 0.7208766 142 10/1/1997 21.33 0.7210325 143 11/1/1997 20.19 0.7078143 144 12/1/1997 18.33 0.7007217 145 1/1/1998 16.72 0.6940107 146 2/1/1998 16.06 0.6976420 147 3/1/1998 15.12 0.7059156 148 4/1/1998 15.35 0.6993985 149 5/1/1998 14.91 0.6919458 150 6/1/1998 13.72 0.6823610 151 7/1/1998 14.17 0.6725402 152 8/1/1998 13.47 0.6516356 153 9/1/1998 15.03 0.6571166 154 10/1/1998 14.46 0.6471654 155 11/1/1998 13.00 0.6491820 156 12/1/1998 11.35 0.6479622 157 1/1/1999 12.52 0.6581545 158 2/1/1999 12.01 0.6676905 159 3/1/1999 14.68 0.6589352 160 4/1/1999 17.31 0.6719979 161 5/1/1999 17.72 0.6844159 162 6/1/1999 17.92 0.6805036 163 7/1/1999 20.10 0.6715917 164 8/1/1999 21.28 0.6697027 165 9/1/1999 23.80 0.6770022 166 10/1/1999 22.69 0.6767731 167 11/1/1999 25.00 0.6814774 168 12/1/1999 26.10 0.6792555 169 1/1/2000 27.26 0.6903217 170 2/1/2000 29.37 0.6890849 171 3/1/2000 29.84 0.6845564 172 4/1/2000 25.72 0.6807815 173 5/1/2000 28.79 0.6685833 174 6/1/2000 31.82 0.6770481 175 7/1/2000 29.70 0.6766816 176 8/1/2000 31.26 0.6743998 177 9/1/2000 33.88 0.6727664 178 10/1/2000 33.11 0.6611570 179 11/1/2000 34.42 0.6482562 180 12/1/2000 28.44 0.6570734 181 1/1/2001 29.59 0.6652475 182 2/1/2001 29.61 0.6572029 183 3/1/2001 27.25 0.6415603 184 4/1/2001 27.49 0.6419309 185 5/1/2001 28.63 0.6488872 186 6/1/2001 27.60 0.6559528 187 7/1/2001 26.43 0.6532532 188 8/1/2001 27.37 0.6493928 189 9/1/2001 26.20 0.6377958 190 10/1/2001 22.17 0.6362537 191 11/1/2001 19.64 0.6280618 192 12/1/2001 19.39 0.6333924 193 1/1/2002 19.72 0.6251172 194 2/1/2002 20.72 0.6264094 195 3/1/2002 24.53 0.6298419 196 4/1/2002 26.18 0.6323111 197 5/1/2002 27.04 0.6450781 198 6/1/2002 25.52 0.6528267 199 7/1/2002 26.97 0.6469979 200 8/1/2002 28.39 0.6371862 201 9/1/2002 29.66 0.6344775 202 10/1/2002 28.84 0.6337136 203 11/1/2002 26.35 0.6363347 204 12/1/2002 29.46 0.6413545 205 1/1/2003 32.95 0.6487609 206 2/1/2003 35.83 0.6613319 207 3/1/2003 33.51 0.6774609 208 4/1/2003 28.17 0.6857770 209 5/1/2003 28.11 0.7225434 210 6/1/2003 30.66 0.7393715 211 7/1/2003 30.76 0.7235366 212 8/1/2003 31.57 0.7161785 213 9/1/2003 28.31 0.7334605 214 10/1/2003 30.34 0.7563724 215 11/1/2003 31.11 0.7616146 216 12/1/2003 32.13 0.7617307 217 1/1/2004 34.31 0.7717240 218 2/1/2004 34.69 0.7519362 219 3/1/2004 36.74 0.7526720 220 4/1/2004 36.75 0.7451565 221 5/1/2004 40.28 0.7252158 222 6/1/2004 38.03 0.7364855 223 7/1/2004 40.78 0.7561437 224 8/1/2004 44.90 0.7617887 225 9/1/2004 45.94 0.7763372 226 10/1/2004 53.28 0.8019889 227 11/1/2004 48.47 0.8355615 228 12/1/2004 43.15 0.8204118 229 1/1/2005 46.84 0.8164598 230 2/1/2005 48.15 0.8063866 231 3/1/2005 54.19 0.8223684 232 4/1/2005 52.98 0.8091270 233 5/1/2005 49.83 0.7964954 234 6/1/2005 56.35 0.8063216 235 7/1/2005 59.00 0.8177284 236 8/1/2005 64.99 0.8303579 237 9/1/2005 65.59 0.8491127 238 10/1/2005 62.26 0.8493290 239 11/1/2005 58.32 0.8463817 240 12/1/2005 59.41 0.8609557 241 1/1/2006 65.49 0.8641549 242 2/1/2006 61.63 0.8703978 243 3/1/2006 62.69 0.8640802 244 4/1/2006 69.44 0.8740495 245 5/1/2006 70.84 0.9009009 246 6/1/2006 70.95 0.8979079 247 7/1/2006 74.41 0.8854259 248 8/1/2006 73.04 0.8942944 249 9/1/2006 63.80 0.8959771 250 10/1/2006 58.89 0.8861320 251 11/1/2006 59.08 0.8803592 252 12/1/2006 61.96 0.8671523 253 1/1/2007 54.51 0.8501233 254 2/1/2007 59.28 0.8539710 255 3/1/2007 60.44 0.8560178 256 4/1/2007 63.98 0.8810573 257 5/1/2007 63.46 0.9131586 258 6/1/2007 67.49 0.9388790 259 7/1/2007 74.12 0.9521996 260 8/1/2007 72.36 0.9452689 261 9/1/2007 79.92 0.9739944 262 10/1/2007 85.80 1.0252204 263 11/1/2007 94.77 1.0339123 264 12/1/2007 91.69 0.9979044 265 1/1/2008 92.97 0.9901970 266 2/1/2008 95.39 1.0014020 267 3/1/2008 105.45 0.9971084 268 4/1/2008 112.58 0.9864852 269 5/1/2008 125.40 1.0007005 270 6/1/2008 133.88 0.9836711 271 7/1/2008 133.37 0.9871668 272 8/1/2008 116.67 0.9492169 273 9/1/2008 104.11 0.9450009 274 10/1/2008 76.61 0.8440956 275 11/1/2008 57.31 0.8216252 276 12/1/2008 41.12 0.8105698 277 1/1/2009 41.71 0.8164598 278 2/1/2009 39.09 0.8030838 279 3/1/2009 47.94 0.7908264 280 4/1/2009 49.65 0.8168600 281 5/1/2009 59.03 0.8674532 282 6/1/2009 69.64 0.8877841 283 7/1/2009 64.15 0.8905513 284 8/1/2009 71.05 0.9197940 285 9/1/2009 69.41 0.9245562 286 10/1/2009 75.72 0.9481369 287 11/1/2009 77.99 0.9440196 288 12/1/2009 74.47 0.9490367 289 1/1/2010 78.33 0.9580379 290 2/1/2010 76.39 0.9458948 291 3/1/2010 81.20 0.9776127 292 4/1/2010 84.29 0.9948269 293 5/1/2010 73.74 0.9612612 294 6/1/2010 75.34 0.9637625 295 7/1/2010 76.32 0.9595087 296 8/1/2010 76.60 0.9611688 297 9/1/2010 75.24 0.9680542 298 10/1/2010 81.89 0.9824148 299 11/1/2010 84.25 0.9872643 300 12/1/2010 89.15 0.9919651 301 1/1/2011 89.17 1.0061374 302 2/1/2011 88.58 1.0125557 303 3/1/2011 102.86 1.0239607 304 4/1/2011 109.53 1.0438413 305 5/1/2011 100.90 1.0330579 306 6/1/2011 96.26 1.0239607 307 7/1/2011 97.30 1.0467916 308 8/1/2011 86.33 1.0186411 309 9/1/2011 85.52 0.9975062 310 10/1/2011 86.32 0.9805844 311 11/1/2011 97.16 0.9758002 312 12/1/2011 98.56 0.9770396 313 1/1/2012 100.27 0.9871668 314 2/1/2012 102.20 1.0033109 315 3/1/2012 106.16 1.0062387 316 4/1/2012 103.32 1.0072522 317 5/1/2012 94.66 0.9903932 318 6/1/2012 82.30 0.9727626 319 7/1/2012 87.90 0.9859988 320 8/1/2012 94.13 1.0076582 321 9/1/2012 94.51 1.0221813 322 10/1/2012 89.49 1.0129660 323 11/1/2012 86.53 1.0030090 324 12/1/2012 87.86 1.0103051 325 1/1/2013 94.76 1.0079629 326 2/1/2013 95.31 0.9902951 327 3/1/2013 92.94 0.9761812 328 4/1/2013 92.02 0.9816433 329 5/1/2013 94.51 0.9807768 330 6/1/2013 95.77 0.9695559 331 7/1/2013 104.67 0.9613536 332 8/1/2013 106.57 0.9608917 333 9/1/2013 106.29 0.9669310 334 10/1/2013 100.54 0.9649715 335 11/1/2013 93.86 0.9536525 336 12/1/2013 97.63 0.9399380 337 1/1/2014 94.62 0.9140768 338 2/1/2014 100.82 0.9046499 339 3/1/2014 100.80 0.9003331 340 4/1/2014 102.07 0.9097525 341 5/1/2014 102.18 0.9179365 342 6/1/2014 105.79 0.9233610 343 7/1/2014 103.59 0.9311854 344 8/1/2014 96.54 0.9152480 345 9/1/2014 93.21 0.9081827 346 10/1/2014 84.40 0.8919015 347 11/1/2014 75.79 0.8830022 348 12/1/2014 59.29 0.8671523 349 1/1/2015 47.22 0.8249464 350 2/1/2015 50.58 0.8000640 351 3/1/2015 47.82 0.7925186 352 4/1/2015 54.45 0.8105698 353 5/1/2015 59.27 0.8212878 354 6/1/2015 59.82 0.8087343 355 7/1/2015 50.90 0.7774236 356 8/1/2015 42.87 0.7606298 357 9/1/2015 45.48 0.7538067 358 10/1/2015 46.22 0.7649939

The Shale Oil Effect?

The global economy is currently in a period of slow economic growth. At the same time, global oil production has continued to increase while global oil demand remains stagnate. The result of these two market forces is an oil supply glut leading to rapidly falling oil prices.

Here is a plot of WTI oil prices. Between 2011 and 2014, oil prices held fairly steady around $100 per barrel. Then in the latter half of 2014, oil prices plunged.



Lets take a look at the relationship between global oil supply and oil prices (measured using WTI).



Up until 75,0000 barrels per day, the relationship between oil prices and World oil production looks like a typical supply curve: upward sloping. After 75,0000 barrels per day, however, the upward sloping relationship breaks down.
 
Now look at how World oil production has evolved across time. Notice that 75,000 barrels per day occurred in 2011 and after 2011, oil supply increased considerably.
 
What is so special about 75,000 barrels per day and the year 2011?  For one thing, US shale oil production started to increase dramatically in 2011.

 

It is hard to make a case that US shale oil production is the only source of excess supply in the global oil market, but the timing does look interesting. US shale oil production has helped the US to dramatically lower oil imports. If foreign oil producers do not cut their oil production, then lower US oil imports means more oil on global markets for which there is no immediate demand. When oil demand is unchanging, small changes in oil supply can have large effects on oil prices. 



R code and data are posted below.

 #########################################################
#  Economic forecasting and analysis
#  Perry Sadorsky
#  Oil supply
#  November 2015
##########################################################


rm(list=ls())
# load libraries
library(fpp)

# import data
global_oil_text <- read.csv("C:/oil/Nov 2015/global_oil_text.csv")
View(global_oil_text)


df = global_oil_text

# tell R that data set is a time series
df = ts(df, start=c(1986,1), frequency=12)
df


# scatter plot

par(font.axis = 2)
par(font.lab = 2)
plot(df[,"price"] ~ df[,"supply"],  xlab="World oil production (thousands bbl per day)", ylab="Oil prices (WTI $/bbl)")
abline(v=75000)


plot( df[,"supply"],  main="World oil production (thousands bbl per day)", ylab="", xlab="")
abline(h=75000,col="blue")
abline(v=2011,col="blue")


plot( df[,"price"],  main="Oil prices (WTI $/bbl)", ylab="", xlab="")
abline(h=100,col="blue")
abline(v=2011,col="blue")

           supply  price
Jan 1986 55650.36  22.93
Feb 1986 55660.37  15.46
Mar 1986 55162.50  12.61
Apr 1986 55266.68  12.84
May 1986 56447.75  15.38
Jun 1986 57220.10  13.43
Jul 1986 58359.09  11.59
Aug 1986 59013.24  15.10
Sep 1986 54978.18  14.87
Oct 1986 55334.80  14.90
Nov 1986 56264.43  15.22
Dec 1986 56434.73  16.11
Jan 1987 55634.93  18.65
Feb 1987 54938.33  17.75
Mar 1987 54196.69  18.30
Apr 1987 54870.27  18.68
May 1987 55674.96  19.44
Jun 1987 55375.71  20.07
Jul 1987 57939.92  21.34
Aug 1987 58737.60  20.31
Sep 1987 58130.08  19.53
Oct 1987 58325.25  19.86
Nov 1987 57862.85  18.85
Dec 1987 57936.91  17.28
Jan 1988 57137.66  17.13
Feb 1988 57217.71  16.80
Mar 1988 57578.92  16.20
Apr 1988 57890.10  17.86
May 1988 57606.93  17.42
Jun 1988 57271.74  16.53
Jul 1988 57695.99  15.50
Aug 1988 58852.67  15.52
Sep 1988 59206.88  14.54
Oct 1988 60890.87  13.77
Nov 1988 61350.14  14.14
Dec 1988 61597.29  16.38
Jan 1989 58706.81  18.02
Feb 1989 58227.58  17.94
Mar 1989 58629.78  19.48
Apr 1989 59059.99  21.07
May 1989 58980.95  20.12
Jun 1989 59017.96  20.05
Jul 1989 59536.22  19.78
Aug 1989 60428.66  18.58
Sep 1989 60511.70  19.59
Oct 1989 61081.98  20.10
Nov 1989 61842.35  19.86
Dec 1989 61485.18  21.10
Jan 1990 60921.39  22.86
Feb 1990 61178.88  22.11
Mar 1990 62082.42  20.39
Apr 1990 61805.93  18.43
May 1990 61238.41  18.20
Jun 1990 60409.37  16.70
Jul 1990 60513.80  18.45
Aug 1990 56965.63  27.31
Sep 1990 59513.98  33.51
Oct 1990 59854.23  36.04
Nov 1990 60672.39  32.33
Dec 1990 60883.96  27.28
Jan 1991 60637.25  25.23
Feb 1991 60326.57  20.48
Mar 1991 60581.69  19.90
Apr 1991 59183.33  20.83
May 1991 59006.36  21.23
Jun 1991 59198.90  20.19
Jul 1991 60191.61  21.40
Aug 1991 59495.34  21.69
Sep 1991 60534.06  21.89
Oct 1991 60489.45  23.23
Nov 1991 60735.22  22.46
Dec 1991 61143.30  19.50
Jan 1992 61259.80  18.79
Feb 1992 60422.66  19.01
Mar 1992 59773.36  18.92
Apr 1992 60133.34  20.23
May 1992 59005.23  20.98
Jun 1992 59247.74  22.39
Jul 1992 59712.62  21.78
Aug 1992 59699.38  21.34
Sep 1992 59960.92  21.88
Oct 1992 60758.67  21.69
Nov 1992 60469.68  20.34
Dec 1992 60790.38  19.41
Jan 1993 60623.27  19.03
Feb 1993 60978.60  20.09
Mar 1993 60263.60  20.32
Apr 1993 59560.25  20.25
May 1993 59746.64  19.95
Jun 1993 59462.45  19.09
Jul 1993 60068.67  17.89
Aug 1993 59890.97  18.01
Sep 1993 59902.29  17.50
Oct 1993 60366.06  18.15
Nov 1993 60429.91  16.61
Dec 1993 60817.46  14.52
Jan 1994 61137.55  15.03
Feb 1994 60959.68  14.78
Mar 1994 60866.98  14.68
Apr 1994 60409.54  16.42
May 1994 60851.50  17.89
Jun 1994 61161.43  19.06
Jul 1994 60767.31  19.66
Aug 1994 60661.91  18.38
Sep 1994 61270.47  17.45
Oct 1994 61768.27  17.72
Nov 1994 61943.60  18.07
Dec 1994 62265.65  17.16
Jan 1995 61841.11  18.04
Feb 1995 62343.97  18.57
Mar 1995 61605.44  18.54
Apr 1995 62402.88  19.90
May 1995 62413.88  19.74
Jun 1995 61555.18  18.45
Jul 1995 62507.51  17.33
Aug 1995 62641.35  18.02
Sep 1995 63036.63  18.23
Oct 1995 62673.54  17.43
Nov 1995 62892.32  17.99
Dec 1995 63286.53  19.03
Jan 1996 63236.80  18.86
Feb 1996 63633.93  19.09
Mar 1996 63486.32  21.33
Apr 1996 63338.64  23.50
May 1996 63338.60  21.17
Jun 1996 63660.57  20.42
Jul 1996 63737.67  21.30
Aug 1996 63386.74  21.90
Sep 1996 63858.81  23.97
Oct 1996 64222.40  24.88
Nov 1996 64670.32  23.71
Dec 1996 65244.27  25.23
Jan 1997 65182.45  25.13
Feb 1997 65541.03  22.18
Mar 1997 65528.60  20.97
Apr 1997 66047.78  19.70
May 1997 65398.23  20.82
Jun 1997 64625.69  19.26
Jul 1997 65070.24  19.66
Aug 1997 65950.21  19.95
Sep 1997 66312.32  19.80
Oct 1997 66826.90  21.33
Nov 1997 66680.22  20.19
Dec 1997 66496.43  18.33
Jan 1998 67706.50  16.72
Feb 1998 68081.35  16.06
Mar 1998 67965.25  15.12
Apr 1998 67828.25  15.35
May 1998 67293.60  14.91
Jun 1998 67014.12  13.72
Jul 1998 66877.51  14.17
Aug 1998 65903.82  13.47
Sep 1998 65984.28  15.03
Oct 1998 66098.41  14.46
Nov 1998 66946.70  13.00
Dec 1998 66771.57  11.35
Jan 1999 66986.56  12.52
Feb 1999 67311.78  12.01
Mar 1999 66988.91  14.68
Apr 1999 65545.34  17.31
May 1999 65351.49  17.72
Jun 1999 64307.10  17.92
Jul 1999 65818.11  20.10
Aug 1999 65704.19  21.28
Sep 1999 65747.39  23.80
Oct 1999 66253.79  22.69
Nov 1999 66236.07  25.00
Dec 1999 65422.50  26.10
Jan 2000 66449.89  27.26
Feb 2000 67065.69  29.37
Mar 2000 67098.94  29.84
Apr 2000 67757.84  25.72
May 2000 68276.19  28.79
Jun 2000 68074.38  31.82
Jul 2000 68695.12  29.70
Aug 2000 69526.13  31.26
Sep 2000 69542.82  33.88
Oct 2000 69980.34  33.11
Nov 2000 70536.25  34.42
Dec 2000 69280.21  28.44
Jan 2001 69197.45  29.59
Feb 2001 68718.72  29.61
Mar 2001 69380.85  27.25
Apr 2001 68451.23  27.49
May 2001 67760.76  28.63
Jun 2001 66206.98  27.60
Jul 2001 68146.13  26.43
Aug 2001 68319.83  27.37
Sep 2001 67852.78  26.20
Oct 2001 67750.04  22.17
Nov 2001 68100.41  19.64
Dec 2001 67692.72  19.39
Jan 2002 66957.16  19.72
Feb 2002 67028.49  20.72
Mar 2002 66824.85  24.53
Apr 2002 66288.45  26.18
May 2002 66859.48  27.04
Jun 2002 66705.97  25.52
Jul 2002 67186.75  26.97
Aug 2002 66914.73  28.39
Sep 2002 67465.25  29.66
Oct 2002 68876.21  28.84
Nov 2002 69006.41  26.35
Dec 2002 67352.85  29.46
Jan 2003 67750.17  32.95
Feb 2003 69368.13  35.83
Mar 2003 69883.66  33.51
Apr 2003 68809.99  28.17
May 2003 68772.78  28.11
Jun 2003 67977.18  30.66
Jul 2003 68603.80  30.76
Aug 2003 69058.90  31.57
Sep 2003 69660.75  28.31
Oct 2003 70623.51  30.34
Nov 2003 70860.66  31.11
Dec 2003 72127.32  32.13
Jan 2004 71908.24  34.31
Feb 2004 71883.68  34.69
Mar 2004 71812.53  36.74
Apr 2004 71780.99  36.75
May 2004 71415.96  40.28
Jun 2004 72973.42  38.03
Jul 2004 73514.84  40.78
Aug 2004 72484.39  44.90
Sep 2004 73112.26  45.94
Oct 2004 73726.30  53.28
Nov 2004 73419.80  48.47
Dec 2004 73093.08  43.15
Jan 2005 73339.66  46.84
Feb 2005 73647.20  48.15
Mar 2005 73950.20  54.19
Apr 2005 74253.15  52.98
May 2005 74361.09  49.83
Jun 2005 73971.47  56.35
Jul 2005 73868.22  59.00
Aug 2005 73843.76  64.99
Sep 2005 73400.82  65.59
Oct 2005 73477.49  62.26
Nov 2005 74002.10  58.32
Dec 2005 74262.01  59.41
Jan 2006 73615.30  65.49
Feb 2006 73618.16  61.63
Mar 2006 73471.33  62.69
Apr 2006 73481.70  69.44
May 2006 73055.31  70.84
Jun 2006 73046.19  70.95
Jul 2006 74057.77  74.41
Aug 2006 73707.14  73.04
Sep 2006 73397.34  63.80
Oct 2006 73742.62  58.89
Nov 2006 73315.94  59.08
Dec 2006 73177.34  61.96
Jan 2007 72880.72  54.51
Feb 2007 73149.19  59.28
Mar 2007 73105.49  60.44
Apr 2007 73334.45  63.98
May 2007 72856.48  63.46
Jun 2007 72399.25  67.49
Jul 2007 73010.59  74.12
Aug 2007 72404.48  72.36
Sep 2007 73153.84  79.92
Oct 2007 73910.88  85.80
Nov 2007 73618.15  94.77
Dec 2007 74124.33  91.69
Jan 2008 74181.22  92.97
Feb 2008 74362.90  95.39
Mar 2008 74548.65 105.45
Apr 2008 73992.41 112.58
May 2008 74319.47 125.40
Jun 2008 74328.01 133.88
Jul 2008 75085.07 133.37
Aug 2008 73955.00 116.67
Sep 2008 72980.02 104.11
Oct 2008 74068.02  76.61
Nov 2008 73884.87  57.31
Dec 2008 73070.30  41.12
Jan 2009 72019.68  41.71
Feb 2009 72494.34  39.09
Mar 2009 72329.59  47.94
Apr 2009 72624.92  49.65
May 2009 72227.01  59.03
Jun 2009 72396.61  69.64
Jul 2009 73358.35  64.15
Aug 2009 72795.45  71.05
Sep 2009 73263.57  69.41
Oct 2009 73747.24  75.72
Nov 2009 73824.71  77.99
Dec 2009 73625.77  74.47
Jan 2010 73632.93  78.33
Feb 2010 74063.96  76.39
Mar 2010 74408.76  81.20
Apr 2010 74333.61  84.29
May 2010 74401.81  73.74
Jun 2010 74467.73  75.34
Jul 2010 74846.09  76.32
Aug 2010 74749.35  76.60
Sep 2010 75035.95  75.24
Oct 2010 74940.15  81.89
Nov 2010 75411.37  84.25
Dec 2010 75345.10  89.15
Jan 2011 75931.03  89.17
Feb 2011 75134.36  88.58
Mar 2011 74107.92 102.86
Apr 2011 73999.31 109.53
May 2011 73290.18 100.90
Jun 2011 74086.23  96.26
Jul 2011 74457.62  97.30
Aug 2011 74918.48  86.33
Sep 2011 74270.84  85.52
Oct 2011 74781.26  86.32
Nov 2011 75749.90  97.16
Dec 2011 76164.56  98.56
Jan 2012 76309.87 100.27
Feb 2012 76605.41 102.20
Mar 2012 76249.59 106.16
Apr 2012 76579.83 103.32
May 2012 75844.27  94.66
Jun 2012 75741.28  82.30
Jul 2012 75935.54  87.90
Aug 2012 75939.75  94.13
Sep 2012 75433.90  94.51
Oct 2012 75967.65  89.49
Nov 2012 76485.91  86.53
Dec 2012 76548.01  87.86
Jan 2013 75841.70  94.76
Feb 2013 75619.31  95.31
Mar 2013 75829.48  92.94
Apr 2013 76265.67  92.02
May 2013 76224.17  94.51
Jun 2013 76206.31  95.77
Jul 2013 76685.55 104.67
Aug 2013 76427.00 106.57
Sep 2013 75902.27 106.29
Oct 2013 76280.91 100.54
Nov 2013 76563.42  93.86
Dec 2013 76906.65  97.63
Jan 2014 77250.37  94.62
Feb 2014 77787.54 100.82
Mar 2014 77182.17 100.80
Apr 2014 77208.42 102.07
May 2014 76966.98 102.18
Jun 2014 77309.30 105.79
Jul 2014 77549.51 103.59
Aug 2014 77731.23  96.54
Sep 2014 78557.70  93.21
Oct 2014 79219.63  84.40
Nov 2014 79111.22  75.79
Dec 2014 79920.56  59.29
Jan 2015 79331.65  47.22
Feb 2015 79289.10  50.58
Mar 2015 80063.86  47.82
Apr 2015 79886.39  54.45
May 2015 79277.44  59.27
Jun 2015 79998.37  59.82
Jul 2015 80415.85  50.90