| Year | Value | | 2022 | 16,216 | | 2021 | 16,398 | | 2020 | 16,639 | | 2019 | 17,059 | | 2018 | 17,417 | | 2017 | 17,777 | | 2016 | 18,231 | | 2015 | 18,795 | | 2014 | 19,462 | | 2013 | 20,635 | | 2012 | 22,227 | | 2011 | 23,634 | | 2010 | 24,681 | | 2009 | 25,197 | | 2008 | 25,011 | | 2007 | 24,083 | | 2006 | 22,735 | | 2005 | 21,834 | | 2004 | 21,390 | | 2003 | 20,824 | | 2002 | 20,104 | | 2001 | 19,207 | | 2000 | 18,184 | | 1999 | 17,176 | | 1998 | 16,245 | | 1997 | 15,375 | | 1996 | 14,570 | | 1995 | 13,842 | | 1994 | 13,247 | | 1993 | 12,798 | | 1992 | 12,452 | | 1991 | 12,182 | | 1990 | 11,957 | | 1989 | 11,723 | | 1988 | 11,493 | | 1987 | 11,309 | | 1986 | 11,167 | | 1985 | 11,033 | | 1984 | 10,796 | | 1983 | 10,442 | | 1982 | 10,055 | | 1981 | 9,659 | | 1980 | 9,266 | | 1979 | 8,890 | | 1978 | 8,534 | | 1977 | 8,221 | | 1976 | 7,974 | | 1975 | 7,759 | | 1974 | 7,479 | | 1973 | 7,081 | | 1972 | 6,646 | | 1971 | 6,232 | | 1970 | 5,845 | | 1969 | 5,488 | | 1968 | 5,165 | | 1967 | 4,892 | | 1966 | 4,699 | | 1965 | 4,620 | | 1964 | 4,771 | | 1963 | 5,019 | | 1962 | 5,165 | | 1961 | 5,248 | | 1960 | 5,282 |
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