| Year | Value | | 2022 | 4,187 | | 2021 | 3,635 | | 2020 | 3,802 | | 2019 | 3,956 | | 2018 | 4,108 | | 2017 | 4,216 | | 2016 | 4,246 | | 2015 | 4,233 | | 2014 | 4,166 | | 2013 | 4,114 | | 2012 | 4,061 | | 2011 | 4,033 | | 2010 | 4,128 | | 2009 | 4,008 | | 2008 | 3,983 | | 2007 | 3,859 | | 2006 | 3,835 | | 2005 | 3,821 | | 2004 | 3,863 | | 2003 | 3,954 | | 2002 | 4,120 | | 2001 | 4,054 | | 2000 | 4,071 | | 1999 | 4,059 | | 1998 | 3,931 | | 1997 | 3,739 | | 1996 | 3,642 | | 1995 | 3,560 | | 1994 | 3,441 | | 1993 | 3,335 | | 1992 | 3,291 | | 1991 | 3,317 | | 1990 | 3,324 | | 1989 | 3,360 | | 1988 | 3,384 | | 1987 | 3,412 | | 1986 | 3,317 | | 1985 | 3,347 | | 1984 | 3,367 | | 1983 | 3,384 | | 1982 | 3,404 | | 1981 | 3,375 | | 1980 | 3,296 | | 1979 | 3,198 | | 1978 | 3,082 | | 1977 | 2,928 | | 1976 | 2,711 | | 1975 | 2,533 | | 1974 | 2,374 | | 1973 | 2,241 | | 1972 | 2,137 | | 1971 | 2,037 | | 1970 | 1,963 | | 1969 | 1,899 | | 1968 | 1,845 | | 1967 | 1,799 | | 1966 | 1,758 | | 1965 | 1,721 | | 1964 | 1,690 | | 1963 | 1,663 | | 1962 | 1,638 | | 1961 | 1,607 | | 1960 | 1,570 |
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