| Year | Value | | 2022 | 21,133 | | 2021 | 21,150 | | 2020 | 21,028 | | 2019 | 20,916 | | 2018 | 20,764 | | 2017 | 20,498 | | 2016 | 20,221 | | 2015 | 19,911 | | 2014 | 19,440 | | 2013 | 18,819 | | 2012 | 18,108 | | 2011 | 17,310 | | 2010 | 16,431 | | 2009 | 15,714 | | 2008 | 15,217 | | 2007 | 14,725 | | 2006 | 14,293 | | 2005 | 13,982 | | 2004 | 13,526 | | 2003 | 12,944 | | 2002 | 12,445 | | 2001 | 11,997 | | 2000 | 11,598 | | 1999 | 11,257 | | 1998 | 10,924 | | 1997 | 10,574 | | 1996 | 10,290 | | 1995 | 10,128 | | 1994 | 10,020 | | 1993 | 9,910 | | 1992 | 9,796 | | 1991 | 9,696 | | 1990 | 9,561 | | 1989 | 9,372 | | 1988 | 9,178 | | 1987 | 8,974 | | 1986 | 8,691 | | 1985 | 8,348 | | 1984 | 8,028 | | 1983 | 7,741 | | 1982 | 7,489 | | 1981 | 7,277 | | 1980 | 7,097 | | 1979 | 6,939 | | 1978 | 6,805 | | 1977 | 6,694 | | 1976 | 6,611 | | 1975 | 6,554 | | 1974 | 6,496 | | 1973 | 6,421 | | 1972 | 6,315 | | 1971 | 6,172 | | 1970 | 5,999 | | 1969 | 5,806 | | 1968 | 5,595 | | 1967 | 5,377 | | 1966 | 5,132 | | 1965 | 4,873 | | 1964 | 4,645 | | 1963 | 4,452 | | 1962 | 4,284 | | 1961 | 4,140 | | 1960 | 4,038 |
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