| Year | Value | | 2022 | 9,585 | | 2021 | 9,540 | | 2020 | 9,463 | | 2019 | 9,428 | | 2018 | 9,606 | | 2017 | 9,886 | | 2016 | 10,117 | | 2015 | 10,254 | | 2014 | 10,328 | | 2013 | 10,317 | | 2012 | 10,279 | | 2011 | 10,151 | | 2010 | 9,919 | | 2009 | 9,684 | | 2008 | 9,511 | | 2007 | 9,317 | | 2006 | 9,086 | | 2005 | 8,968 | | 2004 | 8,911 | | 2003 | 8,842 | | 2002 | 8,854 | | 2001 | 8,937 | | 2000 | 9,085 | | 1999 | 9,273 | | 1998 | 9,461 | | 1997 | 9,610 | | 1996 | 9,643 | | 1995 | 9,559 | | 1994 | 9,358 | | 1993 | 9,062 | | 1992 | 8,765 | | 1991 | 8,490 | | 1990 | 8,218 | | 1989 | 7,997 | | 1988 | 7,808 | | 1987 | 7,567 | | 1986 | 7,304 | | 1985 | 7,042 | | 1984 | 6,780 | | 1983 | 6,544 | | 1982 | 6,350 | | 1981 | 6,182 | | 1980 | 6,054 | | 1979 | 5,989 | | 1978 | 5,973 | | 1977 | 5,965 | | 1976 | 5,942 | | 1975 | 5,950 | | 1974 | 5,992 | | 1973 | 6,012 | | 1972 | 6,009 | | 1971 | 5,852 | | 1970 | 5,509 | | 1969 | 5,030 | | 1968 | 4,672 | | 1967 | 4,450 | | 1966 | 4,251 | | 1965 | 4,066 | | 1964 | 3,917 | | 1963 | 3,793 | | 1962 | 3,690 | | 1961 | 3,584 | | 1960 | 3,478 |
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