| Year | Value | | 2022 | 8,784 | | 2021 | 8,761 | | 2020 | 8,858 | | 2019 | 8,979 | | 2018 | 9,105 | | 2017 | 9,300 | | 2016 | 9,525 | | 2015 | 9,670 | | 2014 | 9,723 | | 2013 | 9,721 | | 2012 | 9,662 | | 2011 | 9,608 | | 2010 | 9,610 | | 2009 | 9,700 | | 2008 | 9,878 | | 2007 | 10,052 | | 2006 | 10,180 | | 2005 | 10,319 | | 2004 | 10,433 | | 2003 | 10,421 | | 2002 | 10,371 | | 2001 | 10,316 | | 2000 | 10,174 | | 1999 | 9,996 | | 1998 | 9,821 | | 1997 | 9,591 | | 1996 | 9,295 | | 1995 | 8,980 | | 1994 | 8,665 | | 1993 | 8,370 | | 1992 | 8,094 | | 1991 | 7,811 | | 1990 | 7,482 | | 1989 | 7,104 | | 1988 | 6,666 | | 1987 | 6,180 | | 1986 | 5,705 | | 1985 | 5,282 | | 1984 | 4,933 | | 1983 | 4,669 | | 1982 | 4,513 | | 1981 | 4,477 | | 1980 | 4,558 | | 1979 | 4,763 | | 1978 | 5,059 | | 1977 | 5,350 | | 1976 | 5,567 | | 1975 | 5,702 | | 1974 | 5,748 | | 1973 | 5,703 | | 1972 | 5,591 | | 1971 | 5,458 | | 1970 | 5,340 | | 1969 | 5,243 | | 1968 | 5,160 | | 1967 | 5,118 | | 1966 | 5,161 | | 1965 | 5,304 | | 1964 | 5,542 | | 1963 | 5,882 | | 1962 | 6,271 | | 1961 | 6,589 | | 1960 | 6,782 |
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