| Year | Value | | 2022 | 4,843 | | 2021 | 4,805 | | 2020 | 4,740 | | 2019 | 4,628 | | 2018 | 4,458 | | 2017 | 4,344 | | 2016 | 4,375 | | 2015 | 4,413 | | 2014 | 4,422 | | 2013 | 4,431 | | 2012 | 4,422 | | 2011 | 4,461 | | 2010 | 4,555 | | 2009 | 4,635 | | 2008 | 4,669 | | 2007 | 4,677 | | 2006 | 4,609 | | 2005 | 4,462 | | 2004 | 4,322 | | 2003 | 4,209 | | 2002 | 4,092 | | 2001 | 4,021 | | 2000 | 4,056 | | 1999 | 4,088 | | 1998 | 4,048 | | 1997 | 3,969 | | 1996 | 3,873 | | 1995 | 3,846 | | 1994 | 3,907 | | 1993 | 3,975 | | 1992 | 4,044 | | 1991 | 4,195 | | 1990 | 4,419 | | 1989 | 4,626 | | 1988 | 4,771 | | 1987 | 4,826 | | 1986 | 4,833 | | 1985 | 4,956 | | 1984 | 5,131 | | 1983 | 5,237 | | 1982 | 5,244 | | 1981 | 5,143 | | 1980 | 5,074 | | 1979 | 5,050 | | 1978 | 4,988 | | 1977 | 4,882 | | 1976 | 4,759 | | 1975 | 4,627 | | 1974 | 4,466 | | 1973 | 4,266 | | 1972 | 4,051 | | 1971 | 3,909 | | 1970 | 3,950 | | 1969 | 4,138 | | 1968 | 4,325 | | 1967 | 4,469 | | 1966 | 4,555 | | 1965 | 4,490 | | 1964 | 4,288 | | 1963 | 4,027 | | 1962 | 3,730 | | 1961 | 3,461 | | 1960 | 3,333 |
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