Year | Value | 2022 | 19,697 | 2021 | 19,517 | 2020 | 19,416 | 2019 | 19,285 | 2018 | 19,221 | 2017 | 19,264 | 2016 | 19,365 | 2015 | 19,581 | 2014 | 19,861 | 2013 | 20,157 | 2012 | 20,526 | 2011 | 20,854 | 2010 | 21,032 | 2009 | 21,192 | 2008 | 21,401 | 2007 | 21,513 | 2006 | 21,562 | 2005 | 21,680 | 2004 | 21,810 | 2003 | 21,851 | 2002 | 21,714 | 2001 | 21,369 | 2000 | 20,891 | 1999 | 20,407 | 1998 | 19,741 | 1997 | 18,954 | 1996 | 17,951 | 1995 | 16,619 | 1994 | 15,222 | 1993 | 14,066 | 1992 | 13,309 | 1991 | 13,195 | 1990 | 13,746 | 1989 | 14,738 | 1988 | 15,934 | 1987 | 17,076 | 1986 | 17,896 | 1985 | 18,231 | 1984 | 18,102 | 1983 | 17,644 | 1982 | 17,025 | 1981 | 16,429 | 1980 | 16,022 | 1979 | 15,823 | 1978 | 15,705 | 1977 | 15,545 | 1976 | 15,215 | 1975 | 14,626 | 1974 | 13,759 | 1973 | 12,687 | 1972 | 11,519 | 1971 | 10,374 | 1970 | 9,338 | 1969 | 8,458 | 1968 | 7,743 | 1967 | 7,212 | 1966 | 6,891 | 1965 | 6,798 | 1964 | 6,917 | 1963 | 7,199 | 1962 | 7,580 | 1961 | 8,008 | 1960 | 8,459 |
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