| Year | Value | | 2014 | 12,993.965579471 | | 2013 | 13,004.023568984 | | 2012 | 12,964.18793893 | | 2011 | 13,245.881927868 | | 2010 | 13,394.902755107 | | 2009 | 12,913.714688301 | | 2008 | 13,663.427968183 | | 2007 | 13,657.452828252 | | 2006 | 13,583.266959339 | | 2005 | 13,704.577048141 | | 2004 | 13,388.589710559 | | 2003 | 13,307.4920085 | | 2002 | 13,296.182299302 | | 2001 | 13,046.614147846 | | 2000 | 13,671.052024006 | | 1999 | 13,281.869982798 | | 1998 | 13,154.763026819 | | 1997 | 12,889.832280117 | | 1996 | 12,854.298907919 | | 1995 | 12,659.607628118 | | 1994 | 12,455.162165654 | | 1993 | 12,261.523782409 | | 1992 | 12,014.958247893 | | 1991 | 12,134.172131504 | | 1990 | 11,713.33170421 | | 1989 | 11,531.93230667 | | 1988 | 11,298.332508517 | | 1987 | 10,886.85825605 | | 1986 | 10,424.42729654 | | 1985 | 10,414.20789832 | | 1984 | 10,282.374642213 | | 1983 | 9,742.0057144813 | | 1982 | 9,544.4609434353 | | 1981 | 9,976.693714973 | | 1980 | 9,862.3654967543 | | 1979 | 9,700.6953855724 | | 1978 | 9,560.5454096188 | | 1977 | 9,337.7240179986 | | 1976 | 8,968.7756552847 | | 1975 | 8,522.3940029541 | | 1974 | 8,449.9284558624 | | 1973 | 8,573.1941540944 | | 1972 | 8,076.4092693524 | | 1971 | 7,517.3046455521 | | 1970 | 7,236.6570430915 | | 1969 | 6,904.8337995925 | | 1968 | 6,385.4593285702 | | 1967 | 5,888.3409154958 | | 1966 | 5,590.3337403337 | | 1965 | 5,234.6850022902 | | 1964 | 4,970.4464560241 | | 1963 | 4,690.4862556938 | | 1962 | 4,433.6060212932 | | 1961 | 4,182.1755012494 | | 1960 | 4,049.786628734 |
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