Year | Value | 2022 | 19,824 | 2021 | 19,855 | 2020 | 20,008 | 2019 | 20,200 | 2018 | 20,508 | 2017 | 20,874 | 2016 | 21,169 | 2015 | 21,408 | 2014 | 21,571 | 2013 | 21,695 | 2012 | 21,738 | 2011 | 21,683 | 2010 | 21,617 | 2009 | 21,639 | 2008 | 21,607 | 2007 | 21,445 | 2006 | 21,204 | 2005 | 20,972 | 2004 | 20,708 | 2003 | 20,192 | 2002 | 19,536 | 2001 | 18,687 | 2000 | 17,335 | 1999 | 15,937 | 1998 | 14,874 | 1997 | 14,257 | 1996 | 14,224 | 1995 | 14,878 | 1994 | 15,962 | 1993 | 17,107 | 1992 | 18,082 | 1991 | 18,642 | 1990 | 18,712 | 1989 | 18,419 | 1988 | 17,946 | 1987 | 17,454 | 1986 | 17,064 | 1985 | 16,823 | 1984 | 16,663 | 1983 | 16,493 | 1982 | 16,264 | 1981 | 15,987 | 1980 | 15,627 | 1979 | 15,109 | 1978 | 14,422 | 1977 | 13,598 | 1976 | 12,657 | 1975 | 11,646 | 1974 | 10,646 | 1973 | 9,764 | 1972 | 9,116 | 1971 | 8,801 | 1970 | 8,869 | 1969 | 9,291 | 1968 | 9,953 | 1967 | 10,702 | 1966 | 11,363 | 1965 | 11,788 | 1964 | 11,923 | 1963 | 11,814 | 1962 | 11,539 | 1961 | 11,194 | 1960 | 10,794 |
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