| Year | Value | | 2022 | 1,157 | | 2021 | 923 | | 2020 | 886 | | 2019 | 856 | | 2018 | 830 | | 2017 | 803 | | 2016 | 770 | | 2015 | 731 | | 2014 | 684 | | 2013 | 641 | | 2012 | 602 | | 2011 | 577 | | 2010 | 577 | | 2009 | 552 | | 2008 | 549 | | 2007 | 541 | | 2006 | 546 | | 2005 | 545 | | 2004 | 554 | | 2003 | 565 | | 2002 | 577 | | 2001 | 567 | | 2000 | 576 | | 1999 | 572 | | 1998 | 555 | | 1997 | 596 | | 1996 | 641 | | 1995 | 629 | | 1994 | 629 | | 1993 | 619 | | 1992 | 604 | | 1991 | 597 | | 1990 | 581 | | 1989 | 567 | | 1988 | 549 | | 1987 | 531 | | 1986 | 496 | | 1985 | 479 | | 1984 | 462 | | 1983 | 447 | | 1982 | 437 | | 1981 | 427 | | 1980 | 417 | | 1979 | 411 | | 1978 | 407 | | 1977 | 414 | | 1976 | 422 | | 1975 | 423 | | 1974 | 420 | | 1973 | 417 | | 1972 | 412 | | 1971 | 396 | | 1970 | 373 | | 1969 | 347 | | 1968 | 324 | | 1967 | 306 | | 1966 | 296 | | 1965 | 294 | | 1964 | 297 | | 1963 | 300 | | 1962 | 302 | | 1961 | 302 | | 1960 | 299 |
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