| Year | Value | | 2022 | 1,047 | | 2021 | 1,029 | | 2020 | 1,016 | | 2019 | 1,007 | | 2018 | 1,000 | | 2017 | 1,000 | | 2016 | 1,004 | | 2015 | 998 | | 2014 | 979 | | 2013 | 955 | | 2012 | 924 | | 2011 | 885 | | 2010 | 836 | | 2009 | 798 | | 2008 | 775 | | 2007 | 757 | | 2006 | 739 | | 2005 | 720 | | 2004 | 700 | | 2003 | 684 | | 2002 | 674 | | 2001 | 669 | | 2000 | 664 | | 1999 | 663 | | 1998 | 663 | | 1997 | 661 | | 1996 | 654 | | 1995 | 645 | | 1994 | 637 | | 1993 | 625 | | 1992 | 613 | | 1991 | 599 | | 1990 | 583 | | 1989 | 564 | | 1988 | 547 | | 1987 | 531 | | 1986 | 515 | | 1985 | 501 | | 1984 | 487 | | 1983 | 476 | | 1982 | 465 | | 1981 | 456 | | 1980 | 448 | | 1979 | 315 | | 1978 | 146 | | 1977 | 108 | | 1976 | 119 | | 1975 | 133 | | 1974 | 150 | | 1973 | 171 | | 1972 | 192 | | 1971 | 209 | | 1970 | 224 | | 1969 | 238 | | 1968 | 249 | | 1967 | 255 | | 1966 | 259 | | 1965 | 263 | | 1964 | 268 | | 1963 | 273 | | 1962 | 276 | | 1961 | 280 | | 1960 | 283 |
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