| Year | Value | | 2022 | 29,501 | | 2021 | 28,708 | | 2020 | 28,114 | | 2019 | 27,666 | | 2018 | 27,309 | | 2017 | 26,941 | | 2016 | 26,479 | | 2015 | 25,894 | | 2014 | 25,195 | | 2013 | 24,425 | | 2012 | 23,631 | | 2011 | 22,851 | | 2010 | 22,064 | | 2009 | 21,258 | | 2008 | 20,444 | | 2007 | 19,640 | | 2006 | 18,891 | | 2005 | 18,241 | | 2004 | 17,720 | | 2003 | 17,330 | | 2002 | 17,055 | | 2001 | 16,810 | | 2000 | 16,521 | | 1999 | 16,203 | | 1998 | 15,873 | | 1997 | 15,541 | | 1996 | 15,216 | | 1995 | 14,899 | | 1994 | 14,584 | | 1993 | 14,266 | | 1992 | 13,911 | | 1991 | 13,518 | | 1990 | 13,137 | | 1989 | 12,805 | | 1988 | 12,548 | | 1987 | 12,377 | | 1986 | 12,280 | | 1985 | 12,235 | | 1984 | 12,227 | | 1983 | 12,243 | | 1982 | 12,280 | | 1981 | 12,372 | | 1980 | 12,547 | | 1979 | 12,770 | | 1978 | 12,952 | | 1977 | 12,987 | | 1976 | 12,826 | | 1975 | 12,484 | | 1974 | 12,065 | | 1973 | 11,699 | | 1972 | 11,320 | | 1971 | 10,881 | | 1970 | 10,517 | | 1969 | 10,327 | | 1968 | 10,321 | | 1967 | 10,408 | | 1966 | 10,418 | | 1965 | 10,119 | | 1964 | 9,387 | | 1963 | 8,289 | | 1962 | 7,027 | | 1961 | 5,924 | | 1960 | 5,461 |
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