| Year | Value | | 2021 | 3,912 | | 2020 | 4,078.636 | | 2019 | 4,253.273 | | 2018 | 4,287.909 | | 2017 | 4,297.545 | | 2016 | 4,344.182 | | 2015 | 4,304.018 | | 2014 | 4,204.555 | | 2013 | 4,144.291 | | 2012 | 4,006.427 | | 2011 | 3,872.364 | | 2010 | 3,749 | | 2009 | 4,297.5 | | 2008 | 4,691.564 | | 2007 | 4,673.289 | | 2006 | 4,664.403 | | 2005 | 4,672.159 | | 2004 | 4,658.978 | | 2003 | 4,654.969 | | 2002 | 4,687.831 | | 2001 | 4,649.089 | | 2000 | 4,682.131 | | 1999 | 4,475.998 | | 1998 | 4,700.975 | | 1997 | 4,685.332 | | 1996 | 4,699.805 | | 1995 | 4,749.327 | | 1994 | 4,668.296 | | 1993 | 4,970 | | 1992 | 4,970 | | 1991 | 4,990 | | 1990 | 5,010 | | 1989 | 5,030 | | 1988 | 5,020 | | 1987 | 5,020 | | 1986 | 5,020 | | 1985 | 5,020 | | 1984 | 5,030 | | 1983 | 5,020 | | 1982 | 5,000 | | 1981 | 4,980 | | 1980 | 4,940 | | 1979 | 4,930 | | 1978 | 4,930 | | 1977 | 4,910 | | 1976 | 4,890 | | 1975 | 4,860 | | 1974 | 4,860 | | 1973 | 4,850 | | 1972 | 4,840 | | 1971 | 4,840 | | 1970 | 4,840 | | 1969 | 4,820 | | 1968 | 4,820 | | 1967 | 4,820 | | 1966 | 4,800 | | 1965 | 4,790 | | 1964 | 4,790 | | 1963 | 4,790 | | 1962 | 4,790 | | 1961 | 4,790 |
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