| Year | Value | | 2022 | 5,892 | | 2021 | 6,010 | | 2020 | 5,995 | | 2019 | 5,963 | | 2018 | 5,563 | | 2017 | 4,940 | | 2016 | 4,682 | | 2015 | 4,485 | | 2014 | 4,377 | | 2013 | 4,341 | | 2012 | 4,354 | | 2011 | 4,359 | | 2010 | 4,359 | | 2009 | 4,365 | | 2008 | 4,320 | | 2007 | 4,199 | | 2006 | 4,015 | | 2005 | 3,794 | | 2004 | 3,628 | | 2003 | 3,575 | | 2002 | 3,576 | | 2001 | 3,714 | | 2000 | 4,045 | | 1999 | 4,445 | | 1998 | 4,867 | | 1997 | 5,224 | | 1996 | 5,484 | | 1995 | 5,715 | | 1994 | 5,937 | | 1993 | 6,135 | | 1992 | 6,331 | | 1991 | 6,566 | | 1990 | 6,797 | | 1989 | 7,019 | | 1988 | 7,228 | | 1987 | 7,374 | | 1986 | 7,412 | | 1985 | 7,334 | | 1984 | 7,171 | | 1983 | 6,979 | | 1982 | 6,762 | | 1981 | 6,505 | | 1980 | 6,282 | | 1979 | 6,103 | | 1978 | 5,986 | | 1977 | 5,939 | | 1976 | 5,891 | | 1975 | 5,865 | | 1974 | 5,826 | | 1973 | 5,740 | | 1972 | 5,696 | | 1971 | 5,561 | | 1970 | 5,302 | | 1969 | 5,060 | | 1968 | 4,850 | | 1967 | 4,695 | | 1966 | 4,612 | | 1965 | 4,571 | | 1964 | 4,528 | | 1963 | 4,479 | | 1962 | 4,425 | | 1961 | 4,378 | | 1960 | 4,360 |
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