| Year | Value | | 2022 | 3,836 | | 2021 | 3,655 | | 2020 | 3,535 | | 2019 | 3,472 | | 2018 | 3,453 | | 2017 | 3,450 | | 2016 | 3,442 | | 2015 | 3,417 | | 2014 | 3,381 | | 2013 | 3,348 | | 2012 | 3,332 | | 2011 | 3,352 | | 2010 | 3,409 | | 2009 | 3,490 | | 2008 | 3,591 | | 2007 | 3,689 | | 2006 | 3,760 | | 2005 | 3,798 | | 2004 | 3,794 | | 2003 | 3,749 | | 2002 | 3,675 | | 2001 | 3,568 | | 2000 | 3,447 | | 1999 | 3,321 | | 1998 | 3,175 | | 1997 | 3,016 | | 1996 | 2,858 | | 1995 | 2,701 | | 1994 | 2,541 | | 1993 | 2,383 | | 1992 | 2,234 | | 1991 | 2,096 | | 1990 | 1,974 | | 1989 | 1,870 | | 1988 | 1,781 | | 1987 | 1,703 | | 1986 | 1,637 | | 1985 | 1,583 | | 1984 | 1,536 | | 1983 | 1,500 | | 1982 | 1,478 | | 1981 | 1,466 | | 1980 | 1,465 | | 1979 | 1,475 | | 1978 | 1,488 | | 1977 | 1,498 | | 1976 | 1,506 | | 1975 | 1,519 | | 1974 | 1,542 | | 1973 | 1,580 | | 1972 | 1,626 | | 1971 | 1,670 | | 1970 | 1,699 | | 1969 | 1,700 | | 1968 | 1,674 | | 1967 | 1,634 | | 1966 | 1,592 | | 1965 | 1,559 | | 1964 | 1,540 | | 1963 | 1,532 | | 1962 | 1,528 | | 1961 | 1,528 | | 1960 | 1,529 |
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