| Year | Value | | 2022 | 5,962 | | 2021 | 5,976 | | 2020 | 6,055 | | 2019 | 6,151 | | 2018 | 6,251 | | 2017 | 6,342 | | 2016 | 6,424 | | 2015 | 6,483 | | 2014 | 6,543 | | 2013 | 6,586 | | 2012 | 6,583 | | 2011 | 6,521 | | 2010 | 6,362 | | 2009 | 6,156 | | 2008 | 5,961 | | 2007 | 5,802 | | 2006 | 5,654 | | 2005 | 5,508 | | 2004 | 5,374 | | 2003 | 5,252 | | 2002 | 5,134 | | 2001 | 5,065 | | 2000 | 5,051 | | 1999 | 5,056 | | 1998 | 5,101 | | 1997 | 5,193 | | 1996 | 5,269 | | 1995 | 5,263 | | 1994 | 5,142 | | 1993 | 4,892 | | 1992 | 4,565 | | 1991 | 4,271 | | 1990 | 4,131 | | 1989 | 4,092 | | 1988 | 4,085 | | 1987 | 4,128 | | 1986 | 4,193 | | 1985 | 4,215 | | 1984 | 4,156 | | 1983 | 4,063 | | 1982 | 3,965 | | 1981 | 3,858 | | 1980 | 3,773 | | 1979 | 3,715 | | 1978 | 3,656 | | 1977 | 3,619 | | 1976 | 3,625 | | 1975 | 3,649 | | 1974 | 3,679 | | 1973 | 3,723 | | 1972 | 3,765 | | 1971 | 3,767 | | 1970 | 3,734 | | 1969 | 3,661 | | 1968 | 3,543 | | 1967 | 3,411 | | 1966 | 3,291 | | 1965 | 3,211 | | 1964 | 3,217 | | 1963 | 3,333 | | 1962 | 3,509 | | 1961 | 3,680 | | 1960 | 3,777 |
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