| Year | Value | | 2022 | 6,612 | | 2021 | 6,590 | | 2020 | 6,548 | | 2019 | 6,456 | | 2018 | 6,351 | | 2017 | 6,249 | | 2016 | 6,161 | | 2015 | 6,092 | | 2014 | 6,036 | | 2013 | 5,972 | | 2012 | 5,907 | | 2011 | 5,857 | | 2010 | 5,833 | | 2009 | 5,795 | | 2008 | 5,755 | | 2007 | 5,666 | | 2006 | 5,522 | | 2005 | 5,373 | | 2004 | 5,220 | | 2003 | 5,053 | | 2002 | 4,875 | | 2001 | 4,683 | | 2000 | 4,477 | | 1999 | 4,315 | | 1998 | 4,198 | | 1997 | 4,083 | | 1996 | 4,000 | | 1995 | 3,946 | | 1994 | 3,864 | | 1993 | 3,754 | | 1992 | 3,631 | | 1991 | 3,526 | | 1990 | 3,450 | | 1989 | 3,383 | | 1988 | 3,321 | | 1987 | 3,278 | | 1986 | 3,192 | | 1985 | 3,065 | | 1984 | 2,978 | | 1983 | 2,914 | | 1982 | 2,859 | | 1981 | 2,838 | | 1980 | 2,839 | | 1979 | 2,647 | | 1978 | 2,419 | | 1977 | 2,396 | | 1976 | 2,420 | | 1975 | 2,419 | | 1974 | 2,426 | | 1973 | 2,453 | | 1972 | 2,505 | | 1971 | 2,578 | | 1970 | 2,602 | | 1969 | 2,582 | | 1968 | 2,594 | | 1967 | 2,620 | | 1966 | 2,531 | | 1965 | 2,394 | | 1964 | 2,367 | | 1963 | 2,373 | | 1962 | 2,376 | | 1961 | 2,346 | | 1960 | 2,278 |
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