| Year | Value | | 2022 | 3,490 | | 2021 | 3,471 | | 2020 | 3,441 | | 2019 | 3,418 | | 2018 | 3,411 | | 2017 | 3,419 | | 2016 | 3,453 | | 2015 | 3,513 | | 2014 | 3,586 | | 2013 | 3,661 | | 2012 | 3,722 | | 2011 | 3,749 | | 2010 | 3,738 | | 2009 | 3,695 | | 2008 | 3,627 | | 2007 | 3,539 | | 2006 | 3,434 | | 2005 | 3,308 | | 2004 | 3,160 | | 2003 | 2,992 | | 2002 | 2,815 | | 2001 | 2,642 | | 2000 | 2,487 | | 1999 | 2,359 | | 1998 | 2,259 | | 1997 | 2,181 | | 1996 | 2,111 | | 1995 | 2,039 | | 1994 | 1,965 | | 1993 | 1,887 | | 1992 | 1,806 | | 1991 | 1,727 | | 1990 | 1,662 | | 1989 | 1,617 | | 1988 | 1,588 | | 1987 | 1,571 | | 1986 | 1,560 | | 1985 | 1,551 | | 1984 | 1,544 | | 1983 | 1,542 | | 1982 | 1,547 | | 1981 | 1,554 | | 1980 | 1,554 | | 1979 | 1,548 | | 1978 | 1,541 | | 1977 | 1,533 | | 1976 | 1,524 | | 1975 | 1,515 | | 1974 | 1,505 | | 1973 | 1,497 | | 1972 | 1,488 | | 1971 | 1,477 | | 1970 | 1,464 | | 1969 | 1,451 | | 1968 | 1,433 | | 1967 | 1,412 | | 1966 | 1,392 | | 1965 | 1,373 | | 1964 | 1,355 | | 1963 | 1,340 | | 1962 | 1,324 | | 1961 | 1,308 | | 1960 | 1,291 |
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