Year Measure 1971 501.44527 1972 543.40311 1973 572.65475 1974 615.46983 1975 642.26153 1976 679.48648 1977 720.51229 1978 776.08112 1979 820.78357 1980 866.59811 1981 905.98692 1982 960.09047 1983 979.85691 1984 1018.86228 1985 1058.25041 1986 1077.10068 1987 1123.02575 1988 1157.54707 1989 1212.90989 1990 1165.39922 1991 1272.21863 1992 1291.62651 1993 1283.95605 1994 1367.8632 1995 1383.93534 1996 1406.01507 1997 1486.2296 1998 1597.0722 1999 1641.7652 2000 1750.55616 2001 1784.87662 2002 1796.76975 2003 1952.53801 2004 1882.39546 2005 1950.98786 2006 1974.46911 2007 1998.7241 2008 1995.43718 2009 1942.76055 2010 1963.31469 2011 2153.71537 2012 2187.22753 2013 2079.19358 2014 2090.17594