| Year | Value | | 2022 | 6,911 | | 2021 | 6,723 | | 2020 | 6,575 | | 2019 | 6,307 | | 2018 | 6,055 | | 2017 | 5,855 | | 2016 | 5,688 | | 2015 | 5,556 | | 2014 | 5,618 | | 2013 | 5,773 | | 2012 | 5,875 | | 2011 | 5,984 | | 2010 | 6,025 | | 2009 | 5,993 | | 2008 | 5,957 | | 2007 | 5,947 | | 2006 | 5,989 | | 2005 | 6,026 | | 2004 | 6,025 | | 2003 | 6,046 | | 2002 | 6,047 | | 2001 | 6,131 | | 2000 | 6,259 | | 1999 | 6,335 | | 1998 | 6,470 | | 1997 | 6,664 | | 1996 | 6,885 | | 1995 | 7,148 | | 1994 | 7,389 | | 1993 | 7,558 | | 1992 | 7,715 | | 1991 | 7,886 | | 1990 | 8,092 | | 1989 | 8,332 | | 1988 | 8,472 | | 1987 | 8,432 | | 1986 | 8,303 | | 1985 | 8,140 | | 1984 | 7,945 | | 1983 | 7,720 | | 1982 | 7,459 | | 1981 | 7,163 | | 1980 | 6,832 | | 1979 | 6,470 | | 1978 | 6,072 | | 1977 | 5,644 | | 1976 | 5,205 | | 1975 | 4,913 | | 1974 | 4,786 | | 1973 | 4,696 | | 1972 | 4,649 | | 1971 | 4,624 | | 1970 | 4,599 | | 1969 | 4,571 | | 1968 | 4,545 | | 1967 | 4,517 | | 1966 | 4,487 | | 1965 | 4,458 | | 1964 | 4,423 | | 1963 | 4,373 | | 1962 | 4,313 | | 1961 | 4,255 | | 1960 | 4,201 |
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