| Year | Value | | 2022 | 21,550 | | 2021 | 20,786 | | 2020 | 20,297 | | 2019 | 19,566 | | 2018 | 18,789 | | 2017 | 18,001 | | 2016 | 17,199 | | 2015 | 16,519 | | 2014 | 16,043 | | 2013 | 15,633 | | 2012 | 14,993 | | 2011 | 14,224 | | 2010 | 13,409 | | 2009 | 12,612 | | 2008 | 11,813 | | 2007 | 10,917 | | 2006 | 10,162 | | 2005 | 9,691 | | 2004 | 9,325 | | 2003 | 8,988 | | 2002 | 8,684 | | 2001 | 8,443 | | 2000 | 8,390 | | 1999 | 8,449 | | 1998 | 8,493 | | 1997 | 8,771 | | 1996 | 9,220 | | 1995 | 9,491 | | 1994 | 9,554 | | 1993 | 9,637 | | 1992 | 9,630 | | 1991 | 9,472 | | 1990 | 9,381 | | 1989 | 9,225 | | 1988 | 9,052 | | 1987 | 8,913 | | 1986 | 8,680 | | 1985 | 8,503 | | 1984 | 8,302 | | 1983 | 7,950 | | 1982 | 7,579 | | 1981 | 7,311 | | 1980 | 7,166 | | 1979 | 7,078 | | 1978 | 7,018 | | 1977 | 6,892 | | 1976 | 6,807 | | 1975 | 6,796 | | 1974 | 6,745 | | 1973 | 6,714 | | 1972 | 6,672 | | 1971 | 6,547 | | 1970 | 6,374 | | 1969 | 6,225 | | 1968 | 6,073 | | 1967 | 5,906 | | 1966 | 5,761 | | 1965 | 5,643 | | 1964 | 5,449 | | 1963 | 5,234 | | 1962 | 5,121 | | 1961 | 5,056 | | 1960 | 4,969 |
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