| Year | Value | | 2024 | 581 | | 2023 | 573 | | 2022 | 561 | | 2021 | 548 | | 2020 | 536 | | 2019 | 521 | | 2018 | 503 | | 2017 | 483 | | 2016 | 462 | | 2015 | 439 | | 2014 | 420 | | 2013 | 408 | | 2012 | 393 | | 2011 | 373 | | 2010 | 351 | | 2009 | 328 | | 2008 | 308 | | 2007 | 292 | | 2006 | 279 | | 2005 | 268 | | 2004 | 258 | | 2003 | 249 | | 2002 | 240 | | 2001 | 235 | | 2000 | 230 | | 1999 | 218 | | 1998 | 202 | | 1997 | 188 | | 1996 | 173 | | 1995 | 166 | | 1994 | 163 | | 1993 | 162 | | 1992 | 165 | | 1991 | 172 | | 1990 | 180 | | 1989 | 186 | | 1988 | 186 | | 1987 | 185 | | 1986 | 186 | | 1985 | 183 | | 1984 | 177 | | 1983 | 173 | | 1982 | 166 | | 1981 | 154 | | 1980 | 148 | | 1979 | 147 | | 1978 | 145 | | 1977 | 138 | | 1976 | 126 | | 1975 | 112 |
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