Year | Value | 2022 | 17,978 | 2021 | 18,326 | 2020 | 18,825 | 2019 | 19,217 | 2018 | 19,489 | 2017 | 19,718 | 2016 | 19,937 | 2015 | 20,279 | 2014 | 20,714 | 2013 | 21,058 | 2012 | 21,351 | 2011 | 21,515 | 2010 | 21,421 | 2009 | 21,374 | 2008 | 21,571 | 2007 | 21,976 | 2006 | 22,507 | 2005 | 23,132 | 2004 | 23,839 | 2003 | 24,459 | 2002 | 24,790 | 2001 | 24,923 | 2000 | 24,893 | 1999 | 24,863 | 1998 | 24,769 | 1997 | 24,686 | 1996 | 24,703 | 1995 | 24,798 | 1994 | 24,891 | 1993 | 24,967 | 1992 | 25,047 | 1991 | 25,067 | 1990 | 25,016 | 1989 | 24,980 | 1988 | 25,010 | 1987 | 25,136 | 1986 | 25,385 | 1985 | 25,773 | 1984 | 26,261 | 1983 | 26,795 | 1982 | 27,318 | 1981 | 27,740 | 1980 | 27,893 | 1979 | 27,817 | 1978 | 27,680 | 1977 | 27,546 | 1976 | 27,444 | 1975 | 27,403 | 1974 | 27,408 | 1973 | 27,442 | 1972 | 27,511 | 1971 | 27,585 | 1970 | 27,486 | 1969 | 27,277 | 1968 | 27,077 | 1967 | 26,755 | 1966 | 26,128 | 1965 | 25,079 | 1964 | 23,688 | 1963 | 22,227 | 1962 | 21,010 | 1961 | 20,363 | 1960 | 20,514 |
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