| Year | Value | | 2022 | 6,233 | | 2021 | 6,123 | | 2020 | 5,972 | | 2019 | 5,816 | | 2018 | 5,685 | | 2017 | 5,666 | | 2016 | 5,796 | | 2015 | 5,972 | | 2014 | 6,167 | | 2013 | 6,367 | | 2012 | 6,523 | | 2011 | 6,649 | | 2010 | 6,706 | | 2009 | 6,679 | | 2008 | 6,658 | | 2007 | 6,629 | | 2006 | 6,516 | | 2005 | 6,371 | | 2004 | 6,241 | | 2003 | 6,107 | | 2002 | 5,975 | | 2001 | 5,845 | | 2000 | 5,702 | | 1999 | 5,543 | | 1998 | 5,385 | | 1997 | 5,262 | | 1996 | 5,182 | | 1995 | 5,150 | | 1994 | 5,189 | | 1993 | 5,278 | | 1992 | 5,390 | | 1991 | 5,485 | | 1990 | 5,426 | | 1989 | 5,228 | | 1988 | 4,975 | | 1987 | 4,651 | | 1986 | 4,291 | | 1985 | 4,062 | | 1984 | 3,970 | | 1983 | 3,926 | | 1982 | 3,939 | | 1981 | 3,983 | | 1980 | 3,980 | | 1979 | 3,921 | | 1978 | 3,842 | | 1977 | 3,747 | | 1976 | 3,652 | | 1975 | 3,583 | | 1974 | 3,551 | | 1973 | 3,555 | | 1972 | 3,588 | | 1971 | 3,626 | | 1970 | 3,641 | | 1969 | 3,629 | | 1968 | 3,626 | | 1967 | 3,663 | | 1966 | 3,734 | | 1965 | 3,798 | | 1964 | 3,814 | | 1963 | 3,768 | | 1962 | 3,668 | | 1961 | 3,537 | | 1960 | 3,464 |
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