| Year | Value | | 2022 | 31,385 | | 2021 | 30,114 | | 2020 | 29,017 | | 2019 | 27,819 | | 2018 | 26,704 | | 2017 | 25,803 | | 2016 | 25,027 | | 2015 | 24,312 | | 2014 | 23,625 | | 2013 | 22,935 | | 2012 | 22,227 | | 2011 | 21,520 | | 2010 | 20,822 | | 2009 | 20,103 | | 2008 | 19,332 | | 2007 | 18,547 | | 2006 | 17,844 | | 2005 | 17,274 | | 2004 | 16,828 | | 2003 | 16,513 | | 2002 | 16,276 | | 2001 | 15,996 | | 2000 | 15,603 | | 1999 | 15,108 | | 1998 | 14,520 | | 1997 | 13,859 | | 1996 | 13,268 | | 1995 | 12,884 | | 1994 | 12,714 | | 1993 | 12,770 | | 1992 | 13,014 | | 1991 | 13,302 | | 1990 | 13,531 | | 1989 | 13,701 | | 1988 | 13,822 | | 1987 | 13,532 | | 1986 | 12,887 | | 1985 | 12,287 | | 1984 | 11,729 | | 1983 | 11,197 | | 1982 | 10,701 | | 1981 | 10,230 | | 1980 | 9,770 | | 1979 | 9,328 | | 1978 | 8,906 | | 1977 | 8,479 | | 1976 | 8,000 | | 1975 | 7,444 | | 1974 | 7,059 | | 1973 | 6,850 | | 1972 | 6,594 | | 1971 | 6,352 | | 1970 | 6,178 | | 1969 | 6,074 | | 1968 | 6,055 | | 1967 | 6,098 | | 1966 | 6,118 | | 1965 | 6,050 | | 1964 | 5,891 | | 1963 | 5,619 | | 1962 | 5,254 | | 1961 | 4,902 | | 1960 | 4,637 |
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