| Year | Value | | 2022 | 6,750 | | 2021 | 6,838 | | 2020 | 6,841 | | 2019 | 6,758 | | 2018 | 6,597 | | 2017 | 6,402 | | 2016 | 6,191 | | 2015 | 5,961 | | 2014 | 5,716 | | 2013 | 5,465 | | 2012 | 5,197 | | 2011 | 4,955 | | 2010 | 4,752 | | 2009 | 4,557 | | 2008 | 4,364 | | 2007 | 4,179 | | 2006 | 3,998 | | 2005 | 3,828 | | 2004 | 3,669 | | 2003 | 3,526 | | 2002 | 3,401 | | 2001 | 3,302 | | 2000 | 3,249 | | 1999 | 3,200 | | 1998 | 3,119 | | 1997 | 3,015 | | 1996 | 2,903 | | 1995 | 2,793 | | 1994 | 2,688 | | 1993 | 2,590 | | 1992 | 2,493 | | 1991 | 2,393 | | 1990 | 2,292 | | 1989 | 2,194 | | 1988 | 2,104 | | 1987 | 2,027 | | 1986 | 1,966 | | 1985 | 1,923 | | 1984 | 1,892 | | 1983 | 1,872 | | 1982 | 1,865 | | 1981 | 1,849 | | 1980 | 1,823 | | 1979 | 1,816 | | 1978 | 1,829 | | 1977 | 1,853 | | 1976 | 1,877 | | 1975 | 1,888 | | 1974 | 1,883 | | 1973 | 1,860 | | 1972 | 1,823 | | 1971 | 1,780 | | 1970 | 1,771 | | 1969 | 1,928 | | 1968 | 2,206 | | 1967 | 2,457 | | 1966 | 2,672 | | 1965 | 2,827 | | 1964 | 2,895 | | 1963 | 2,873 | | 1962 | 2,774 | | 1961 | 2,627 | | 1960 | 2,530 |
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