| Year | Value | | 2022 | 3,545 | | 2021 | 3,029 | | 2020 | 3,156 | | 2019 | 3,294 | | 2018 | 3,442 | | 2017 | 3,532 | | 2016 | 3,526 | | 2015 | 3,459 | | 2014 | 3,343 | | 2013 | 3,264 | | 2012 | 3,231 | | 2011 | 3,238 | | 2010 | 3,360 | | 2009 | 3,325 | | 2008 | 3,360 | | 2007 | 3,283 | | 2006 | 3,302 | | 2005 | 3,367 | | 2004 | 3,491 | | 2003 | 3,655 | | 2002 | 3,879 | | 2001 | 3,867 | | 2000 | 3,909 | | 1999 | 3,912 | | 1998 | 3,826 | | 1997 | 3,683 | | 1996 | 3,609 | | 1995 | 3,530 | | 1994 | 3,413 | | 1993 | 3,312 | | 1992 | 3,286 | | 1991 | 3,341 | | 1990 | 3,381 | | 1989 | 3,450 | | 1988 | 3,506 | | 1987 | 3,551 | | 1986 | 3,437 | | 1985 | 3,427 | | 1984 | 3,384 | | 1983 | 3,321 | | 1982 | 3,257 | | 1981 | 3,153 | | 1980 | 3,020 | | 1979 | 2,883 | | 1978 | 2,734 | | 1977 | 2,550 | | 1976 | 2,319 | | 1975 | 2,143 | | 1974 | 1,992 | | 1973 | 1,868 | | 1972 | 1,778 | | 1971 | 1,701 | | 1970 | 1,654 | | 1969 | 1,629 | | 1968 | 1,621 | | 1967 | 1,622 | | 1966 | 1,626 | | 1965 | 1,632 | | 1964 | 1,644 | | 1963 | 1,661 | | 1962 | 1,677 | | 1961 | 1,684 | | 1960 | 1,676 |
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