Year Measure 1960 1110.2634 1961 1246.01076 1962 1317.93138 1963 1506.01165 1964 1676.44593 1965 1775.83609 1966 1984.16675 1967 2253.66096 1968 2513.33353 1969 2863.17993 1970 3222.00393 1971 3415.68824 1972 3737.26537 1973 4090.99825 1974 3967.08484 1975 4028.66714 1976 4310.62064 1977 4444.77135 1978 4670.1074 1979 4862.75999 1980 4717.68766 1981 4754.37746 1982 4696.62049 1983 4960.93377 1984 5184.88893 1985 5327.79867 1986 5327.79113 1987 5639.94889 1988 5904.78987 1989 6236.9229 1990 6805.54004 1991 7009.02995 1992 7034.6135 1993 7094.01298 1994 7522.57104 1995 7695.71664 1996 7835.41274 1997 7991.00407 1998 8003.9557 1999 8147.38887 2000 8299.40951 2001 8162.01464 2002 8266.0991 2003 8164.93368 2004 8393.25772 2005 8539.01059 2006 8542.47814 2007 8710.0257 2008 8270.00773 2009 8020.27381 2010 8594.90903 2011 8099.5987 2012 7998.34677 2013 7988.58331 2014 7819.71464