| Year | Value | | 2014 | 8,898.9409509156 | | 2013 | 9,003.6426417772 | | 2012 | 9,014.4748020452 | | 2011 | 9,102.6610737664 | | 2010 | 9,223.9102992278 | | 2009 | 8,847.8600983859 | | 2008 | 9,271.5331672405 | | 2007 | 9,318.5164770444 | | 2006 | 9,228.1776065845 | | 2005 | 9,225.4699569179 | | 2004 | 9,061.3392616106 | | 2003 | 8,921.7935763673 | | 2002 | 8,854.6549480385 | | 2001 | 8,702.8692619693 | | 2000 | 8,797.4922638223 | | 1999 | 8,523.9548333807 | | 1998 | 8,381.0900938939 | | 1997 | 8,245.8838739345 | | 1996 | 8,150.3997198503 | | 1995 | 7,996.4816036005 | | 1994 | 7,827.1687685882 | | 1993 | 7,687.604469689 | | 1992 | 7,619.606771455 | | 1991 | 7,657.9196682641 | | 1990 | 7,480.7373194118 | | 1989 | 7,561.6445533658 | | 1988 | 7,370.8485390814 | | 1987 | 7,111.3543352431 | | 1986 | 6,819.6657102477 | | 1985 | 6,730.3856835755 | | 1984 | 6,545.0929044328 | | 1983 | 6,220.2626696487 | | 1982 | 6,038.7593143903 | | 1981 | 6,153.2671682698 | | 1980 | 6,072.6178031566 | | 1979 | 6,007.8839606993 | | 1978 | 5,827.8413180828 | | 1977 | 5,616.6697279691 | | 1976 | 5,418.6010608451 | | 1975 | 5,104.1871563686 | | 1974 | 5,084.7530144783 | | 1973 | 5,068.0480390117 | | 1972 | 4,745.4225786251 | | 1971 | 4,429.1970934308 | | 1970 | 4,536.5406912333 | | 1969 | 4,183.9185422984 | | 1968 | 3,856.0834311959 | | 1967 | 3,564.7482497 | | 1966 | 3,371.339279295 | | 1965 | 3,160.9223139065 | | 1964 | 3,010.2949860933 | | 1963 | 2,809.3448763489 | | 1962 | 2,627.9954007849 | | 1961 | 2,465.1229524647 | | 1960 | 2,342.6210123122 |
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