| Year | Value | | 2022 | 6,763 | | 2021 | 6,737 | | 2020 | 6,736 | | 2019 | 6,798 | | 2018 | 6,913 | | 2017 | 7,023 | | 2016 | 7,083 | | 2015 | 7,066 | | 2014 | 6,976 | | 2013 | 6,824 | | 2012 | 6,630 | | 2011 | 6,426 | | 2010 | 6,209 | | 2009 | 5,950 | | 2008 | 5,664 | | 2007 | 5,374 | | 2006 | 5,100 | | 2005 | 4,856 | | 2004 | 4,653 | | 2003 | 4,485 | | 2002 | 4,336 | | 2001 | 4,227 | | 2000 | 4,200 | | 1999 | 4,210 | | 1998 | 4,192 | | 1997 | 4,144 | | 1996 | 4,069 | | 1995 | 3,959 | | 1994 | 3,816 | | 1993 | 3,660 | | 1992 | 3,505 | | 1991 | 3,361 | | 1990 | 3,242 | | 1989 | 3,140 | | 1988 | 3,032 | | 1987 | 2,918 | | 1986 | 2,804 | | 1985 | 2,693 | | 1984 | 2,585 | | 1983 | 2,487 | | 1982 | 2,404 | | 1981 | 2,352 | | 1980 | 2,311 | | 1979 | 2,244 | | 1978 | 2,159 | | 1977 | 2,074 | | 1976 | 2,007 | | 1975 | 1,962 | | 1974 | 1,937 | | 1973 | 1,926 | | 1972 | 1,919 | | 1971 | 1,906 | | 1970 | 1,884 | | 1969 | 1,920 | | 1968 | 2,021 | | 1967 | 2,121 | | 1966 | 2,210 | | 1965 | 2,284 | | 1964 | 2,335 | | 1963 | 2,362 | | 1962 | 2,367 | | 1961 | 2,352 | | 1960 | 2,313 |
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