| Year | Value | | 2022 | 22,275 | | 2021 | 21,656 | | 2020 | 21,054 | | 2019 | 20,228 | | 2018 | 19,104 | | 2017 | 18,130 | | 2016 | 17,523 | | 2015 | 17,322 | | 2014 | 17,079 | | 2013 | 16,530 | | 2012 | 16,000 | | 2011 | 15,583 | | 2010 | 15,264 | | 2009 | 14,576 | | 2008 | 13,707 | | 2007 | 13,128 | | 2006 | 12,684 | | 2005 | 12,252 | | 2004 | 11,761 | | 2003 | 11,229 | | 2002 | 10,803 | | 2001 | 10,439 | | 2000 | 10,132 | | 1999 | 9,917 | | 1998 | 9,632 | | 1997 | 9,447 | | 1996 | 9,793 | | 1995 | 10,370 | | 1994 | 9,580 | | 1993 | 9,529 | | 1992 | 10,446 | | 1991 | 10,436 | | 1990 | 10,492 | | 1989 | 10,507 | | 1988 | 10,494 | | 1987 | 10,365 | | 1986 | 10,152 | | 1985 | 9,979 | | 1984 | 9,765 | | 1983 | 9,534 | | 1982 | 9,283 | | 1981 | 9,096 | | 1980 | 8,631 | | 1979 | 8,098 | | 1978 | 7,823 | | 1977 | 7,479 | | 1976 | 7,187 | | 1975 | 6,985 | | 1974 | 6,783 | | 1973 | 6,590 | | 1972 | 6,743 | | 1971 | 6,918 | | 1970 | 6,819 | | 1969 | 6,745 | | 1968 | 6,661 | | 1967 | 6,545 | | 1966 | 6,404 | | 1965 | 6,285 | | 1964 | 6,102 | | 1963 | 5,860 | | 1962 | 5,692 | | 1961 | 5,473 | | 1960 | 5,237 |
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