| Year | Value | | 2022 | 5,771 | | 2021 | 5,693 | | 2020 | 5,646 | | 2019 | 5,658 | | 2018 | 5,665 | | 2017 | 5,646 | | 2016 | 5,624 | | 2015 | 5,596 | | 2014 | 5,593 | | 2013 | 5,672 | | 2012 | 5,817 | | 2011 | 5,880 | | 2010 | 5,788 | | 2009 | 5,694 | | 2008 | 5,666 | | 2007 | 5,665 | | 2006 | 5,649 | | 2005 | 5,619 | | 2004 | 5,632 | | 2003 | 5,676 | | 2002 | 5,734 | | 2001 | 5,801 | | 2000 | 5,862 | | 1999 | 5,904 | | 1998 | 5,927 | | 1997 | 5,908 | | 1996 | 5,804 | | 1995 | 5,660 | | 1994 | 5,555 | | 1993 | 5,511 | | 1992 | 5,550 | | 1991 | 5,676 | | 1990 | 5,869 | | 1989 | 6,103 | | 1988 | 6,344 | | 1987 | 6,558 | | 1986 | 6,642 | | 1985 | 6,565 | | 1984 | 6,410 | | 1983 | 6,234 | | 1982 | 6,078 | | 1981 | 5,971 | | 1980 | 5,913 | | 1979 | 5,883 | | 1978 | 5,859 | | 1977 | 5,812 | | 1976 | 5,684 | | 1975 | 5,500 | | 1974 | 5,334 | | 1973 | 5,161 | | 1972 | 4,972 | | 1971 | 4,795 | | 1970 | 4,631 | | 1969 | 4,482 | | 1968 | 4,354 | | 1967 | 4,230 | | 1966 | 4,112 | | 1965 | 4,002 | | 1964 | 3,886 | | 1963 | 3,774 | | 1962 | 3,682 | | 1961 | 3,591 | | 1960 | 3,496 |
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