| Year | Value | | 2022 | 3,987 | | 2021 | 4,049 | | 2020 | 4,123 | | 2019 | 4,221 | | 2018 | 4,341 | | 2017 | 4,443 | | 2016 | 4,525 | | 2015 | 4,563 | | 2014 | 4,556 | | 2013 | 4,547 | | 2012 | 4,542 | | 2011 | 4,565 | | 2010 | 4,651 | | 2009 | 4,776 | | 2008 | 4,917 | | 2007 | 5,075 | | 2006 | 5,225 | | 2005 | 5,342 | | 2004 | 5,416 | | 2003 | 5,469 | | 2002 | 5,517 | | 2001 | 5,570 | | 2000 | 5,630 | | 1999 | 5,685 | | 1998 | 5,718 | | 1997 | 5,715 | | 1996 | 5,682 | | 1995 | 5,636 | | 1994 | 5,595 | | 1993 | 5,572 | | 1992 | 5,570 | | 1991 | 5,595 | | 1990 | 5,672 | | 1989 | 5,791 | | 1988 | 5,905 | | 1987 | 5,996 | | 1986 | 6,059 | | 1985 | 6,096 | | 1984 | 6,097 | | 1983 | 6,039 | | 1982 | 5,913 | | 1981 | 5,713 | | 1980 | 5,483 | | 1979 | 5,278 | | 1978 | 5,101 | | 1977 | 4,943 | | 1976 | 4,807 | | 1975 | 4,694 | | 1974 | 4,602 | | 1973 | 4,484 | | 1972 | 4,332 | | 1971 | 4,165 | | 1970 | 3,959 | | 1969 | 3,715 | | 1968 | 3,498 | | 1967 | 3,325 | | 1966 | 3,175 | | 1965 | 3,072 | | 1964 | 3,012 | | 1963 | 2,980 | | 1962 | 2,956 | | 1961 | 2,932 | | 1960 | 2,908 |
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