| Year | Value | | 2022 | 890 | | 2021 | 864 | | 2020 | 860 | | 2019 | 874 | | 2018 | 900 | | 2017 | 935 | | 2016 | 970 | | 2015 | 995 | | 2014 | 1,012 | | 2013 | 1,019 | | 2012 | 1,016 | | 2011 | 1,007 | | 2010 | 991 | | 2009 | 970 | | 2008 | 949 | | 2007 | 926 | | 2006 | 897 | | 2005 | 863 | | 2004 | 823 | | 2003 | 773 | | 2002 | 715 | | 2001 | 667 | | 2000 | 634 | | 1999 | 613 | | 1998 | 603 | | 1997 | 598 | | 1996 | 593 | | 1995 | 581 | | 1994 | 567 | | 1993 | 555 | | 1992 | 543 | | 1991 | 536 | | 1990 | 536 | | 1989 | 541 | | 1988 | 542 | | 1987 | 542 | | 1986 | 540 | | 1985 | 537 | | 1984 | 531 | | 1983 | 524 | | 1982 | 515 | | 1981 | 502 | | 1980 | 486 | | 1979 | 468 | | 1978 | 445 | | 1977 | 423 | | 1976 | 403 | | 1975 | 384 | | 1974 | 368 | | 1973 | 359 | | 1972 | 350 | | 1971 | 347 | | 1970 | 349 | | 1969 | 349 | | 1968 | 346 | | 1967 | 341 | | 1966 | 333 | | 1965 | 323 | | 1964 | 314 | | 1963 | 304 | | 1962 | 296 | | 1961 | 292 | | 1960 | 290 |
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