| Year | Value | | 2022 | 21,067 | | 2021 | 20,427 | | 2020 | 20,171 | | 2019 | 20,241 | | 2018 | 20,143 | | 2017 | 19,643 | | 2016 | 18,720 | | 2015 | 17,434 | | 2014 | 16,140 | | 2013 | 15,147 | | 2012 | 14,401 | | 2011 | 13,682 | | 2010 | 12,707 | | 2009 | 11,370 | | 2008 | 9,848 | | 2007 | 8,421 | | 2006 | 7,235 | | 2005 | 6,318 | | 2004 | 5,668 | | 2003 | 5,302 | | 2002 | 5,143 | | 2001 | 5,071 | | 2000 | 5,033 | | 1999 | 4,986 | | 1998 | 4,934 | | 1997 | 4,889 | | 1996 | 4,854 | | 1995 | 4,822 | | 1994 | 4,798 | | 1993 | 4,807 | | 1992 | 4,802 | | 1991 | 4,738 | | 1990 | 4,658 | | 1989 | 4,567 | | 1988 | 4,406 | | 1987 | 4,206 | | 1986 | 4,056 | | 1985 | 3,986 | | 1984 | 3,976 | | 1983 | 4,012 | | 1982 | 4,073 | | 1981 | 4,110 | | 1980 | 4,063 | | 1979 | 3,940 | | 1978 | 3,804 | | 1977 | 3,693 | | 1976 | 3,617 | | 1975 | 3,563 | | 1974 | 3,507 | | 1973 | 3,424 | | 1972 | 3,304 | | 1971 | 3,150 | | 1970 | 2,992 | | 1969 | 2,858 | | 1968 | 2,740 | | 1967 | 2,631 | | 1966 | 2,520 | | 1965 | 2,457 | | 1964 | 2,397 | | 1963 | 2,296 | | 1962 | 2,200 | | 1961 | 2,086 | | 1960 | 1,946 |
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