| Year | Value | | 2022 | 9,046 | | 2021 | 9,202 | | 2020 | 9,409 | | 2019 | 9,583 | | 2018 | 9,614 | | 2017 | 9,515 | | 2016 | 9,411 | | 2015 | 9,349 | | 2014 | 9,355 | | 2013 | 9,531 | | 2012 | 9,822 | | 2011 | 9,991 | | 2010 | 10,004 | | 2009 | 9,950 | | 2008 | 9,816 | | 2007 | 9,650 | | 2006 | 9,582 | | 2005 | 9,670 | | 2004 | 9,840 | | 2003 | 10,028 | | 2002 | 10,293 | | 2001 | 10,554 | | 2000 | 10,720 | | 1999 | 10,823 | | 1998 | 10,839 | | 1997 | 10,790 | | 1996 | 10,823 | | 1995 | 11,020 | | 1994 | 11,313 | | 1993 | 11,638 | | 1992 | 11,927 | | 1991 | 12,156 | | 1990 | 12,362 | | 1989 | 12,602 | | 1988 | 12,843 | | 1987 | 13,005 | | 1986 | 13,064 | | 1985 | 13,007 | | 1984 | 12,837 | | 1983 | 12,568 | | 1982 | 12,211 | | 1981 | 11,787 | | 1980 | 11,320 | | 1979 | 10,769 | | 1978 | 10,192 | | 1977 | 9,655 | | 1976 | 9,100 | | 1975 | 8,530 | | 1974 | 8,022 | | 1973 | 7,539 | | 1972 | 7,035 | | 1971 | 6,593 | | 1970 | 6,262 | | 1969 | 6,057 | | 1968 | 5,974 | | 1967 | 6,041 | | 1966 | 6,241 | | 1965 | 6,533 | | 1964 | 6,894 | | 1963 | 7,294 | | 1962 | 7,667 | | 1961 | 8,003 | | 1960 | 8,202 |
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