Year Measure 1971 1495.16339 1972 1405.32363 1973 1508.76409 1974 1735.05877 1975 1724.23377 1976 1738.97395 1977 1809.81997 1978 1899.94555 1979 1914.59916 1980 2128.87225 1981 2221.63758 1982 2155.27354 1983 2262.82007 1984 2151.23124 1985 2075.45782 1986 2115.75429 1987 2063.81024 1988 1942.96193 1989 1946.64572 1990 1993.133 1991 2033.66783 1992 2223.7099 1993 2025.74066 1994 2298.02868 1995 2110.94745 1996 2204.17378 1997 2150.67102 1998 2220.39827 1999 2076.402 2000 2093.75437 2001 2126.76293 2002 2266.51576 2003 2047.27251 2004 2142.99806 2005 2102.16665 2006 2302.79354 2007 2095.11142 2008 2305.69645 2009 2274.51287 2010 2493.4664 2011 2280.72791 2012 2444.10422 2013 2268.05596