Year | Value | 2022 | 21,118 | 2021 | 20,972 | 2020 | 20,802 | 2019 | 20,606 | 2018 | 20,360 | 2017 | 20,180 | 2016 | 20,176 | 2015 | 20,296 | 2014 | 20,495 | 2013 | 20,824 | 2012 | 21,220 | 2011 | 21,552 | 2010 | 21,819 | 2009 | 21,973 | 2008 | 22,055 | 2007 | 22,026 | 2006 | 21,921 | 2005 | 21,835 | 2004 | 21,857 | 2003 | 21,868 | 2002 | 21,650 | 2001 | 21,334 | 2000 | 21,038 | 1999 | 20,827 | 1998 | 20,459 | 1997 | 19,953 | 1996 | 19,159 | 1995 | 17,933 | 1994 | 16,552 | 1993 | 15,379 | 1992 | 14,639 | 1991 | 14,598 | 1990 | 15,282 | 1989 | 16,418 | 1988 | 17,711 | 1987 | 18,856 | 1986 | 19,575 | 1985 | 19,726 | 1984 | 19,370 | 1983 | 18,693 | 1982 | 17,899 | 1981 | 17,188 | 1980 | 16,743 | 1979 | 16,573 | 1978 | 16,536 | 1977 | 16,502 | 1976 | 16,344 | 1975 | 15,965 | 1974 | 15,331 | 1973 | 14,492 | 1972 | 13,539 | 1971 | 12,568 | 1970 | 11,652 | 1969 | 10,861 | 1968 | 10,239 | 1967 | 9,826 | 1966 | 9,663 | 1965 | 9,771 | 1964 | 10,095 | 1963 | 10,525 | 1962 | 10,948 | 1961 | 11,290 | 1960 | 11,557 |
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