| Year | Value | | 2022 | 3,973 | | 2021 | 4,013 | | 2020 | 4,067 | | 2019 | 4,134 | | 2018 | 4,216 | | 2017 | 4,297 | | 2016 | 4,375 | | 2015 | 4,452 | | 2014 | 4,525 | | 2013 | 4,594 | | 2012 | 4,656 | | 2011 | 4,712 | | 2010 | 4,895 | | 2009 | 5,208 | | 2008 | 5,526 | | 2007 | 5,854 | | 2006 | 6,185 | | 2005 | 6,517 | | 2004 | 6,846 | | 2003 | 7,165 | | 2002 | 7,472 | | 2001 | 7,761 | | 2000 | 7,912 | | 1999 | 7,595 | | 1998 | 6,910 | | 1997 | 6,213 | | 1996 | 5,521 | | 1995 | 5,088 | | 1994 | 4,973 | | 1993 | 4,974 | | 1992 | 4,975 | | 1991 | 4,977 | | 1990 | 4,929 | | 1989 | 4,799 | | 1988 | 4,553 | | 1987 | 4,293 | | 1986 | 4,014 | | 1985 | 3,723 | | 1984 | 3,426 | | 1983 | 3,132 | | 1982 | 2,844 | | 1981 | 2,564 | | 1980 | 2,328 | | 1979 | 2,334 | | 1978 | 2,486 | | 1977 | 2,644 | | 1976 | 2,806 | | 1975 | 2,969 | | 1974 | 3,128 | | 1973 | 3,202 | | 1972 | 3,180 | | 1971 | 3,089 | | 1970 | 3,037 | | 1969 | 3,246 | | 1968 | 3,697 | | 1967 | 4,107 | | 1966 | 4,206 | | 1965 | 4,219 | | 1964 | 4,226 | | 1963 | 4,229 | | 1962 | 4,232 | | 1961 | 4,237 | | 1960 | 4,245 |
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