| Year | Value | | 2022 | 700 | | 2021 | 660 | | 2020 | 623 | | 2019 | 588 | | 2018 | 557 | | 2017 | 534 | | 2016 | 520 | | 2015 | 510 | | 2014 | 501 | | 2013 | 495 | | 2012 | 487 | | 2011 | 473 | | 2010 | 461 | | 2009 | 454 | | 2008 | 449 | | 2007 | 447 | | 2006 | 448 | | 2005 | 449 | | 2004 | 447 | | 2003 | 442 | | 2002 | 445 | | 2001 | 452 | | 2000 | 456 | | 1999 | 463 | | 1998 | 473 | | 1997 | 483 | | 1996 | 495 | | 1995 | 513 | | 1994 | 533 | | 1993 | 552 | | 1992 | 570 | | 1991 | 581 | | 1990 | 583 | | 1989 | 575 | | 1988 | 560 | | 1987 | 536 | | 1986 | 509 | | 1985 | 476 | | 1984 | 440 | | 1983 | 402 | | 1982 | 364 | | 1981 | 327 | | 1980 | 294 | | 1979 | 267 | | 1978 | 250 | | 1977 | 240 | | 1976 | 235 | | 1975 | 232 | | 1974 | 227 | | 1973 | 214 | | 1972 | 194 | | 1971 | 171 | | 1970 | 150 | | 1969 | 133 | | 1968 | 121 | | 1967 | 116 | | 1966 | 112 | | 1965 | 110 | | 1964 | 105 | | 1963 | 100 | | 1962 | 95 | | 1961 | 91 | | 1960 | 88 |
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