| Year | Value | | 2022 | 3,359 | | 2021 | 3,351 | | 2020 | 3,321 | | 2019 | 3,282 | | 2018 | 3,250 | | 2017 | 3,232 | | 2016 | 3,249 | | 2015 | 3,306 | | 2014 | 3,396 | | 2013 | 3,504 | | 2012 | 3,611 | | 2011 | 3,696 | | 2010 | 3,739 | | 2009 | 3,728 | | 2008 | 3,679 | | 2007 | 3,601 | | 2006 | 3,492 | | 2005 | 3,360 | | 2004 | 3,218 | | 2003 | 3,064 | | 2002 | 2,888 | | 2001 | 2,724 | | 2000 | 2,587 | | 1999 | 2,450 | | 1998 | 2,314 | | 1997 | 2,182 | | 1996 | 2,049 | | 1995 | 1,918 | | 1994 | 1,800 | | 1993 | 1,698 | | 1992 | 1,609 | | 1991 | 1,532 | | 1990 | 1,474 | | 1989 | 1,433 | | 1988 | 1,407 | | 1987 | 1,396 | | 1986 | 1,393 | | 1985 | 1,393 | | 1984 | 1,399 | | 1983 | 1,410 | | 1982 | 1,417 | | 1981 | 1,423 | | 1980 | 1,439 | | 1979 | 1,459 | | 1978 | 1,484 | | 1977 | 1,517 | | 1976 | 1,546 | | 1975 | 1,569 | | 1974 | 1,575 | | 1973 | 1,557 | | 1972 | 1,520 | | 1971 | 1,475 | | 1970 | 1,436 | | 1969 | 1,418 | | 1968 | 1,419 | | 1967 | 1,424 | | 1966 | 1,432 | | 1965 | 1,439 | | 1964 | 1,444 | | 1963 | 1,453 | | 1962 | 1,467 | | 1961 | 1,487 | | 1960 | 1,502 |
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