| Year | Value | | 2022 | 18,220 | | 2021 | 17,944 | | 2020 | 17,610 | | 2019 | 17,117 | | 2018 | 16,508 | | 2017 | 15,817 | | 2016 | 15,054 | | 2015 | 14,230 | | 2014 | 13,568 | | 2013 | 13,148 | | 2012 | 12,824 | | 2011 | 12,615 | | 2010 | 12,500 | | 2009 | 12,211 | | 2008 | 11,748 | | 2007 | 11,342 | | 2006 | 11,006 | | 2005 | 10,736 | | 2004 | 10,545 | | 2003 | 10,361 | | 2002 | 10,110 | | 2001 | 9,780 | | 2000 | 9,409 | | 1999 | 9,012 | | 1998 | 8,587 | | 1997 | 8,156 | | 1996 | 7,770 | | 1995 | 7,460 | | 1994 | 7,202 | | 1993 | 6,973 | | 1992 | 6,768 | | 1991 | 6,587 | | 1990 | 6,397 | | 1989 | 6,201 | | 1988 | 6,042 | | 1987 | 5,916 | | 1986 | 5,833 | | 1985 | 5,756 | | 1984 | 5,660 | | 1983 | 5,568 | | 1982 | 5,487 | | 1981 | 5,408 | | 1980 | 5,315 | | 1979 | 5,187 | | 1978 | 5,030 | | 1977 | 4,855 | | 1976 | 4,660 | | 1975 | 4,460 | | 1974 | 4,273 | | 1973 | 4,099 | | 1972 | 3,943 | | 1971 | 3,798 | | 1970 | 3,663 | | 1969 | 3,545 | | 1968 | 3,445 | | 1967 | 3,346 | | 1966 | 3,234 | | 1965 | 3,122 | | 1964 | 3,019 | | 1963 | 2,921 | | 1962 | 2,833 | | 1961 | 2,759 | | 1960 | 2,694 |
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