| Year | Value | | 2022 | 5,811 | | 2021 | 5,652 | | 2020 | 5,586 | | 2019 | 5,619 | | 2018 | 5,736 | | 2017 | 5,891 | | 2016 | 6,030 | | 2015 | 6,118 | | 2014 | 6,141 | | 2013 | 6,113 | | 2012 | 6,052 | | 2011 | 5,979 | | 2010 | 5,889 | | 2009 | 5,803 | | 2008 | 5,743 | | 2007 | 5,687 | | 2006 | 5,619 | | 2005 | 5,530 | | 2004 | 5,418 | | 2003 | 5,280 | | 2002 | 5,110 | | 2001 | 4,908 | | 2000 | 4,711 | | 1999 | 4,549 | | 1998 | 4,377 | | 1997 | 4,184 | | 1996 | 4,000 | | 1995 | 3,832 | | 1994 | 3,672 | | 1993 | 3,548 | | 1992 | 3,478 | | 1991 | 3,449 | | 1990 | 3,457 | | 1989 | 3,499 | | 1988 | 3,583 | | 1987 | 3,690 | | 1986 | 3,793 | | 1985 | 3,878 | | 1984 | 3,934 | | 1983 | 3,942 | | 1982 | 3,899 | | 1981 | 3,818 | | 1980 | 3,710 | | 1979 | 3,600 | | 1978 | 3,522 | | 1977 | 3,464 | | 1976 | 3,386 | | 1975 | 3,286 | | 1974 | 3,194 | | 1973 | 3,127 | | 1972 | 3,074 | | 1971 | 3,023 | | 1970 | 2,950 | | 1969 | 2,849 | | 1968 | 2,786 | | 1967 | 2,776 | | 1966 | 2,764 | | 1965 | 2,694 | | 1964 | 2,569 | | 1963 | 2,446 | | 1962 | 2,340 | | 1961 | 2,253 | | 1960 | 2,176 |
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