Year Measure 1971 126.51329 1972 126.99016 1973 143.48294 1974 148.40219 1975 155.71182 1976 162.40367 1977 181.33908 1978 181.6024 1979 205.79449 1980 210.69596 1981 224.36433 1982 221.19045 1983 231.43618 1984 238.27363 1985 282.63176 1986 279.35507 1987 326.30206 1988 337.86955 1989 331.52359 1990 367.88685 1991 351.57201 1992 328.32581 1993 341.55707 1994 304.36055 1995 353.82413 1996 401.85083 1997 415.16819 1998 445.25007 1999 447.52259 2000 492.16136 2001 499.77133 2002 521.62583 2003 545.79154 2004 544.82463 2005 580.05569 2006 591.13645 2007 643.23015 2008 665.08668 2009 633.35242 2010 627.10668 2011 674.24206 2012 646.74688 2013 653.63138 2014 630.13553