| Year | Value | | 2022 | 9,143 | | 2021 | 9,361 | | 2020 | 9,501 | | 2019 | 9,553 | | 2018 | 9,551 | | 2017 | 9,494 | | 2016 | 9,438 | | 2015 | 9,441 | | 2014 | 9,505 | | 2013 | 9,618 | | 2012 | 9,720 | | 2011 | 9,777 | | 2010 | 9,850 | | 2009 | 9,934 | | 2008 | 9,933 | | 2007 | 9,900 | | 2006 | 9,860 | | 2005 | 9,737 | | 2004 | 9,568 | | 2003 | 9,388 | | 2002 | 9,142 | | 2001 | 8,824 | | 2000 | 8,499 | | 1999 | 8,204 | | 1998 | 7,947 | | 1997 | 7,720 | | 1996 | 7,503 | | 1995 | 7,229 | | 1994 | 6,866 | | 1993 | 6,454 | | 1992 | 6,017 | | 1991 | 5,595 | | 1990 | 5,234 | | 1989 | 4,943 | | 1988 | 4,734 | | 1987 | 4,600 | | 1986 | 4,528 | | 1985 | 4,520 | | 1984 | 4,589 | | 1983 | 4,754 | | 1982 | 4,984 | | 1981 | 5,226 | | 1980 | 5,432 | | 1979 | 5,516 | | 1978 | 5,468 | | 1977 | 5,349 | | 1976 | 5,208 | | 1975 | 5,088 | | 1974 | 4,989 | | 1973 | 4,902 | | 1972 | 4,851 | | 1971 | 4,882 | | 1970 | 5,011 | | 1969 | 5,231 | | 1968 | 5,551 | | 1967 | 5,919 | | 1966 | 6,218 | | 1965 | 6,385 | | 1964 | 6,430 | | 1963 | 6,360 | | 1962 | 6,201 | | 1961 | 6,026 | | 1960 | 5,885 |
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