| Year | Value | | 2022 | 24,370 | | 2021 | 24,450 | | 2020 | 24,398 | | 2019 | 23,921 | | 2018 | 23,149 | | 2017 | 22,313 | | 2016 | 21,477 | | 2015 | 20,687 | | 2014 | 19,929 | | 2013 | 19,204 | | 2012 | 18,514 | | 2011 | 17,810 | | 2010 | 17,103 | | 2009 | 16,411 | | 2008 | 15,735 | | 2007 | 15,075 | | 2006 | 14,436 | | 2005 | 13,816 | | 2004 | 13,230 | | 2003 | 12,686 | | 2002 | 12,181 | | 2001 | 11,712 | | 2000 | 11,278 | | 1999 | 10,875 | | 1998 | 10,501 | | 1997 | 10,155 | | 1996 | 9,811 | | 1995 | 9,446 | | 1994 | 9,061 | | 1993 | 8,657 | | 1992 | 8,247 | | 1991 | 7,841 | | 1990 | 7,447 | | 1989 | 7,067 | | 1988 | 6,702 | | 1987 | 6,347 | | 1986 | 6,001 | | 1985 | 5,687 | | 1984 | 5,424 | | 1983 | 5,193 | | 1982 | 4,977 | | 1981 | 4,783 | | 1980 | 4,619 | | 1979 | 4,489 | | 1978 | 4,396 | | 1977 | 4,350 | | 1976 | 4,322 | | 1975 | 4,294 | | 1974 | 4,255 | | 1973 | 4,192 | | 1972 | 4,124 | | 1971 | 4,061 | | 1970 | 3,996 | | 1969 | 3,926 | | 1968 | 3,848 | | 1967 | 3,765 | | 1966 | 3,683 | | 1965 | 3,609 | | 1964 | 3,546 | | 1963 | 3,494 | | 1962 | 3,449 | | 1961 | 3,403 | | 1960 | 3,356 |
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