| Year | Value | | 2022 | 21,002 | | 2021 | 20,586 | | 2020 | 20,122 | | 2019 | 19,483 | | 2018 | 18,667 | | 2017 | 17,969 | | 2016 | 17,484 | | 2015 | 17,193 | | 2014 | 16,786 | | 2013 | 16,138 | | 2012 | 15,492 | | 2011 | 14,915 | | 2010 | 14,403 | | 2009 | 13,717 | | 2008 | 12,983 | | 2007 | 12,438 | | 2006 | 11,990 | | 2005 | 11,586 | | 2004 | 11,185 | | 2003 | 10,792 | | 2002 | 10,489 | | 2001 | 10,236 | | 2000 | 10,029 | | 1999 | 9,881 | | 1998 | 9,686 | | 1997 | 9,581 | | 1996 | 9,807 | | 1995 | 10,112 | | 1994 | 9,634 | | 1993 | 9,872 | | 1992 | 10,684 | | 1991 | 10,759 | | 1990 | 10,898 | | 1989 | 10,998 | | 1988 | 11,069 | | 1987 | 11,029 | | 1986 | 10,887 | | 1985 | 10,750 | | 1984 | 10,563 | | 1983 | 10,345 | | 1982 | 10,104 | | 1981 | 9,893 | | 1980 | 9,534 | | 1979 | 9,164 | | 1978 | 8,960 | | 1977 | 8,714 | | 1976 | 8,468 | | 1975 | 8,219 | | 1974 | 7,920 | | 1973 | 7,595 | | 1972 | 7,538 | | 1971 | 7,486 | | 1970 | 7,219 | | 1969 | 7,032 | | 1968 | 6,911 | | 1967 | 6,832 | | 1966 | 6,755 | | 1965 | 6,685 | | 1964 | 6,581 | | 1963 | 6,442 | | 1962 | 6,335 | | 1961 | 6,202 | | 1960 | 6,076 |
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