| Year | Value | | 2022 | 21,712 | | 2021 | 20,760 | | 2020 | 19,824 | | 2019 | 18,920 | | 2018 | 18,129 | | 2017 | 17,522 | | 2016 | 17,131 | | 2015 | 16,886 | | 2014 | 16,652 | | 2013 | 16,385 | | 2012 | 16,058 | | 2011 | 15,669 | | 2010 | 15,230 | | 2009 | 14,754 | | 2008 | 14,250 | | 2007 | 13,729 | | 2006 | 13,181 | | 2005 | 12,594 | | 2004 | 11,943 | | 2003 | 11,332 | | 2002 | 10,779 | | 2001 | 10,301 | | 2000 | 10,020 | | 1999 | 9,894 | | 1998 | 9,707 | | 1997 | 9,390 | | 1996 | 9,036 | | 1995 | 8,668 | | 1994 | 8,266 | | 1993 | 7,848 | | 1992 | 7,519 | | 1991 | 7,331 | | 1990 | 7,251 | | 1989 | 7,297 | | 1988 | 7,463 | | 1987 | 7,640 | | 1986 | 7,787 | | 1985 | 7,915 | | 1984 | 8,025 | | 1983 | 8,118 | | 1982 | 8,191 | | 1981 | 8,223 | | 1980 | 8,170 | | 1979 | 8,001 | | 1978 | 7,747 | | 1977 | 7,454 | | 1976 | 7,153 | | 1975 | 6,869 | | 1974 | 6,606 | | 1973 | 6,368 | | 1972 | 6,157 | | 1971 | 5,971 | | 1970 | 5,805 | | 1969 | 5,655 | | 1968 | 5,520 | | 1967 | 5,409 | | 1966 | 5,322 | | 1965 | 5,248 | | 1964 | 5,184 | | 1963 | 5,128 | | 1962 | 5,079 | | 1961 | 5,031 | | 1960 | 4,981 |
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