| Year | Value | | 2022 | 3,615 | | 2021 | 3,574 | | 2020 | 3,550 | | 2019 | 3,545 | | 2018 | 3,538 | | 2017 | 3,506 | | 2016 | 3,456 | | 2015 | 3,392 | | 2014 | 3,318 | | 2013 | 3,263 | | 2012 | 3,245 | | 2011 | 3,271 | | 2010 | 3,330 | | 2009 | 3,414 | | 2008 | 3,503 | | 2007 | 3,571 | | 2006 | 3,597 | | 2005 | 3,585 | | 2004 | 3,538 | | 2003 | 3,464 | | 2002 | 3,373 | | 2001 | 3,270 | | 2000 | 3,163 | | 1999 | 3,051 | | 1998 | 2,923 | | 1997 | 2,786 | | 1996 | 2,649 | | 1995 | 2,515 | | 1994 | 2,385 | | 1993 | 2,266 | | 1992 | 2,169 | | 1991 | 2,087 | | 1990 | 1,996 | | 1989 | 1,876 | | 1988 | 1,740 | | 1987 | 1,599 | | 1986 | 1,464 | | 1985 | 1,367 | | 1984 | 1,317 | | 1983 | 1,304 | | 1982 | 1,315 | | 1981 | 1,338 | | 1980 | 1,383 | | 1979 | 1,448 | | 1978 | 1,504 | | 1977 | 1,552 | | 1976 | 1,595 | | 1975 | 1,631 | | 1974 | 1,661 | | 1973 | 1,687 | | 1972 | 1,710 | | 1971 | 1,729 | | 1970 | 1,747 | | 1969 | 1,766 | | 1968 | 1,784 | | 1967 | 1,802 | | 1966 | 1,819 | | 1965 | 1,831 | | 1964 | 1,841 | | 1963 | 1,846 | | 1962 | 1,847 | | 1961 | 1,846 | | 1960 | 1,844 |
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