| Year | Value | | 2024 | 8,165 | | 2023 | 8,172 | | 2022 | 8,180 | | 2021 | 8,182 | | 2020 | 8,176 | | 2019 | 8,184 | | 2018 | 8,216 | | 2017 | 8,240 | | 2016 | 8,255 | | 2015 | 8,269 | | 2014 | 8,289 | | 2013 | 8,311 | | 2012 | 8,379 | | 2011 | 8,499 | | 2010 | 8,624 | | 2009 | 8,750 | | 2008 | 8,870 | | 2007 | 8,986 | | 2006 | 9,097 | | 2005 | 9,172 | | 2004 | 9,134 | | 2003 | 9,020 | | 2002 | 8,914 | | 2001 | 8,813 | | 2000 | 8,714 | | 1999 | 8,607 | | 1998 | 8,482 | | 1997 | 8,338 | | 1996 | 8,174 | | 1995 | 7,981 | | 1994 | 7,781 | | 1993 | 7,591 | | 1992 | 7,406 | | 1991 | 7,224 | | 1990 | 7,048 | | 1989 | 6,907 | | 1988 | 6,787 | | 1987 | 6,664 | | 1986 | 6,543 | | 1985 | 6,418 | | 1984 | 6,290 | | 1983 | 6,168 | | 1982 | 6,056 | | 1981 | 5,949 | | 1980 | 5,906 | | 1979 | 5,938 | | 1978 | 5,977 | | 1977 | 6,010 | | 1976 | 6,041 | | 1975 | 6,061 |
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