| Year | Value | | 2022 | 23,913 | | 2021 | 22,760 | | 2020 | 21,729 | | 2019 | 20,864 | | 2018 | 20,105 | | 2017 | 19,450 | | 2016 | 18,868 | | 2015 | 18,334 | | 2014 | 17,828 | | 2013 | 17,339 | | 2012 | 16,869 | | 2011 | 16,436 | | 2010 | 16,054 | | 2009 | 15,711 | | 2008 | 15,368 | | 2007 | 15,032 | | 2006 | 14,702 | | 2005 | 14,397 | | 2004 | 14,125 | | 2003 | 13,854 | | 2002 | 13,589 | | 2001 | 13,342 | | 2000 | 13,094 | | 1999 | 12,838 | | 1998 | 12,583 | | 1997 | 12,325 | | 1996 | 12,025 | | 1995 | 11,666 | | 1994 | 11,251 | | 1993 | 11,319 | | 1992 | 11,497 | | 1991 | 11,240 | | 1990 | 10,934 | | 1989 | 10,580 | | 1988 | 10,179 | | 1987 | 9,746 | | 1986 | 9,318 | | 1985 | 8,912 | | 1984 | 8,518 | | 1983 | 8,137 | | 1982 | 7,781 | | 1981 | 7,456 | | 1980 | 7,176 | | 1979 | 6,942 | | 1978 | 6,752 | | 1977 | 6,590 | | 1976 | 6,443 | | 1975 | 6,310 | | 1974 | 6,193 | | 1973 | 6,093 | | 1972 | 5,998 | | 1971 | 5,901 | | 1970 | 5,790 | | 1969 | 5,661 | | 1968 | 5,519 | | 1967 | 5,372 | | 1966 | 5,241 | | 1965 | 5,144 | | 1964 | 5,079 | | 1963 | 5,038 | | 1962 | 5,003 | | 1961 | 4,967 | | 1960 | 4,937 |
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