| Year | Value | | 2021 | 718 | | 2020 | 718 | | 2019 | 716 | | 2018 | 714 | | 2017 | 712 | | 2016 | 709 | | 2015 | 709 | | 2014 | 709 | | 2013 | 707 | | 2012 | 706 | | 2011 | 704 | | 2010 | 702 | | 2009 | 700 | | 2008 | 700 | | 2007 | 695 | | 2006 | 694 | | 2005 | 689 | | 2004 | 689 | | 2003 | 687 | | 2002 | 675 | | 2001 | 670 | | 2000 | 670 | | 1999 | 670 | | 1998 | 670 | | 1997 | 670 | | 1996 | 670 | | 1995 | 670 | | 1994 | 670 | | 1993 | 670 | | 1992 | 670 | | 1991 | 670 | | 1990 | 670 | | 1989 | 670 | | 1988 | 670 | | 1987 | 670 | | 1986 | 670 | | 1985 | 670 | | 1984 | 670 | | 1983 | 670 | | 1982 | 670 | | 1981 | 670 | | 1980 | 670 | | 1979 | 670 | | 1978 | 670 | | 1977 | 670 | | 1976 | 670 | | 1975 | 670 | | 1974 | 670 | | 1973 | 670 | | 1972 | 670 | | 1971 | 670 | | 1970 | 670 | | 1969 | 670 | | 1968 | 670 | | 1967 | 670 | | 1966 | 670 | | 1965 | 670 | | 1964 | 670 | | 1963 | 670 | | 1962 | 670 | | 1961 | 670 |
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