| Year | Value | | 2022 | 6,771 | | 2021 | 6,721 | | 2020 | 6,679 | | 2019 | 6,710 | | 2018 | 6,810 | | 2017 | 6,920 | | 2016 | 7,031 | | 2015 | 7,127 | | 2014 | 7,196 | | 2013 | 7,241 | | 2012 | 7,261 | | 2011 | 7,249 | | 2010 | 7,208 | | 2009 | 7,120 | | 2008 | 6,999 | | 2007 | 6,871 | | 2006 | 6,761 | | 2005 | 6,675 | | 2004 | 6,601 | | 2003 | 6,541 | | 2002 | 6,501 | | 2001 | 6,467 | | 2000 | 6,418 | | 1999 | 6,353 | | 1998 | 6,287 | | 1997 | 6,224 | | 1996 | 6,154 | | 1995 | 6,079 | | 1994 | 5,997 | | 1993 | 5,959 | | 1992 | 5,964 | | 1991 | 5,950 | | 1990 | 5,945 | | 1989 | 6,007 | | 1988 | 6,068 | | 1987 | 6,058 | | 1986 | 6,027 | | 1985 | 6,007 | | 1984 | 5,985 | | 1983 | 5,930 | | 1982 | 5,801 | | 1981 | 5,603 | | 1980 | 5,398 | | 1979 | 5,278 | | 1978 | 5,241 | | 1977 | 5,232 | | 1976 | 5,241 | | 1975 | 5,199 | | 1974 | 5,059 | | 1973 | 4,858 | | 1972 | 4,619 | | 1971 | 4,359 | | 1970 | 4,125 | | 1969 | 4,003 | | 1968 | 3,977 | | 1967 | 3,959 | | 1966 | 3,911 | | 1965 | 3,807 | | 1964 | 3,635 | | 1963 | 3,395 | | 1962 | 3,119 | | 1961 | 2,859 | | 1960 | 2,642 |
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