| Year | Value | | 2022 | 22,690 | | 2021 | 22,243 | | 2020 | 21,727 | | 2019 | 21,089 | | 2018 | 20,379 | | 2017 | 19,657 | | 2016 | 18,991 | | 2015 | 18,394 | | 2014 | 17,858 | | 2013 | 17,365 | | 2012 | 16,888 | | 2011 | 16,398 | | 2010 | 15,752 | | 2009 | 14,982 | | 2008 | 14,270 | | 2007 | 13,652 | | 2006 | 13,131 | | 2005 | 12,693 | | 2004 | 12,311 | | 2003 | 11,970 | | 2002 | 11,668 | | 2001 | 11,371 | | 2000 | 11,081 | | 1999 | 10,839 | | 1998 | 10,641 | | 1997 | 10,456 | | 1996 | 10,269 | | 1995 | 10,076 | | 1994 | 9,877 | | 1993 | 9,697 | | 1992 | 9,518 | | 1991 | 9,339 | | 1990 | 9,201 | | 1989 | 9,113 | | 1988 | 9,058 | | 1987 | 9,027 | | 1986 | 9,019 | | 1985 | 9,032 | | 1984 | 9,054 | | 1983 | 9,062 | | 1982 | 8,989 | | 1981 | 8,784 | | 1980 | 8,508 | | 1979 | 8,246 | | 1978 | 8,061 | | 1977 | 8,004 | | 1976 | 8,080 | | 1975 | 8,236 | | 1974 | 8,474 | | 1973 | 8,609 | | 1972 | 8,337 | | 1971 | 7,798 | | 1970 | 7,219 | | 1969 | 6,620 | | 1968 | 6,040 | | 1967 | 5,524 | | 1966 | 5,117 | | 1965 | 4,883 | | 1964 | 4,848 | | 1963 | 4,962 | | 1962 | 5,134 | | 1961 | 5,262 | | 1960 | 5,213 |
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