| Year | Value | | 2022 | 1,517 | | 2021 | 1,433 | | 2020 | 1,361 | | 2019 | 1,298 | | 2018 | 1,229 | | 2017 | 1,163 | | 2016 | 1,101 | | 2015 | 1,032 | | 2014 | 974 | | 2013 | 935 | | 2012 | 896 | | 2011 | 864 | | 2010 | 843 | | 2009 | 831 | | 2008 | 819 | | 2007 | 806 | | 2006 | 784 | | 2005 | 764 | | 2004 | 755 | | 2003 | 757 | | 2002 | 766 | | 2001 | 768 | | 2000 | 764 | | 1999 | 760 | | 1998 | 756 | | 1997 | 754 | | 1996 | 758 | | 1995 | 759 | | 1994 | 756 | | 1993 | 765 | | 1992 | 785 | | 1991 | 814 | | 1990 | 851 | | 1989 | 881 | | 1988 | 902 | | 1987 | 911 | | 1986 | 910 | | 1985 | 902 | | 1984 | 896 | | 1983 | 887 | | 1982 | 875 | | 1981 | 864 | | 1980 | 850 | | 1979 | 829 | | 1978 | 803 | | 1977 | 777 | | 1976 | 746 | | 1975 | 715 | | 1974 | 688 | | 1973 | 664 | | 1972 | 647 | | 1971 | 636 | | 1970 | 621 | | 1969 | 599 | | 1968 | 566 | | 1967 | 519 | | 1966 | 472 | | 1965 | 441 | | 1964 | 425 | | 1963 | 431 | | 1962 | 456 | | 1961 | 478 | | 1960 | 481 |
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