| Year | Value | | 2024 | 611 | | 2023 | 621 | | 2022 | 629 | | 2021 | 630 | | 2020 | 629 | | 2019 | 633 | | 2018 | 643 | | 2017 | 660 | | 2016 | 686 | | 2015 | 713 | | 2014 | 721 | | 2013 | 716 | | 2012 | 713 | | 2011 | 705 | | 2010 | 693 | | 2009 | 688 | | 2008 | 689 | | 2007 | 690 | | 2006 | 693 | | 2005 | 690 | | 2004 | 675 | | 2003 | 648 | | 2002 | 614 | | 2001 | 574 | | 2000 | 533 | | 1999 | 498 | | 1998 | 469 | | 1997 | 439 | | 1996 | 411 | | 1995 | 384 | | 1994 | 354 | | 1993 | 329 | | 1992 | 318 | | 1991 | 310 | | 1990 | 297 | | 1989 | 292 | | 1988 | 282 | | 1987 | 262 | | 1986 | 243 | | 1985 | 225 | | 1984 | 210 | | 1983 | 199 | | 1982 | 187 | | 1981 | 178 | | 1980 | 178 | | 1979 | 184 | | 1978 | 189 | | 1977 | 196 | | 1976 | 210 | | 1975 | 227 |
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