| Year | Value | | 2014 | 5,130.3902533003 | | 2013 | 5,409.6264217189 | | 2012 | 5,449.2594726721 | | 2011 | 5,471.9334745627 | | 2010 | 5,700.8558644427 | | 2009 | 5,643.1285945674 | | 2008 | 6,015.7268606895 | | 2007 | 6,102.3967677228 | | 2006 | 6,200.5541127704 | | 2005 | 6,270.9840594905 | | 2004 | 6,138.7541371882 | | 2003 | 6,174.5508958394 | | 2002 | 6,142.7498336337 | | 2001 | 6,141.9825512228 | | 2000 | 6,114.5292591856 | | 1999 | 6,007.4844162139 | | 1998 | 5,908.8714902307 | | 1997 | 5,831.9575470283 | | 1996 | 5,815.8284042742 | | 1995 | 5,575.8084890423 | | 1994 | 5,380.2642651538 | | 1993 | 5,491.9891181032 | | 1992 | 5,452.3933334123 | | 1991 | 5,451.6771706182 | | 1990 | 5,356.575210001 | | 1989 | 5,295.2245268653 | | 1988 | 5,232.7376492199 | | 1987 | 5,082.4398063098 | | 1986 | 4,953.6535762104 | | 1985 | 4,826.7145259152 | | 1984 | 4,597.7396930761 | | 1983 | 4,549.1752875693 | | 1982 | 4,480.3354128709 | | 1981 | 4,572.9538462582 | | 1980 | 4,683.9327391151 | | 1979 | 4,922.9157328012 | | 1978 | 4,729.8493870722 | | 1977 | 4,668.4231690033 | | 1976 | 4,587.6885150152 | | 1975 | 4,492.4216285051 | | 1974 | 4,534.2542751309 | | 1973 | 4,671.7182974064 | | 1972 | 4,372.6369464501 | | 1971 | 4,254.6524118454 | | 1970 | 4,166.9324015396 | | 1969 | 4,006.33096899 | | 1968 | 3,762.5901756331 | | 1967 | 3,506.8870623694 | | 1966 | 3,425.8030870015 | | 1965 | 3,330.1838796424 | | 1964 | 3,127.462962963 | | 1963 | 3,002.0876048462 | | 1962 | 2,780.6572769953 | | 1961 | 2,553.6931818182 | | 1960 | 2,412.1374045801 |
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