| Year | Value | | 2024 | 605 | | 2023 | 608 | | 2022 | 612 | | 2021 | 610 | | 2020 | 604 | | 2019 | 598 | | 2018 | 589 | | 2017 | 572 | | 2016 | 550 | | 2015 | 525 | | 2014 | 503 | | 2013 | 486 | | 2012 | 482 | | 2011 | 488 | | 2010 | 486 | | 2009 | 472 | | 2008 | 449 | | 2007 | 416 | | 2006 | 379 | | 2005 | 343 | | 2004 | 317 | | 2003 | 298 | | 2002 | 288 | | 2001 | 277 | | 2000 | 261 | | 1999 | 256 | | 1998 | 256 | | 1997 | 255 | | 1996 | 252 | | 1995 | 241 | | 1994 | 223 | | 1993 | 204 | | 1992 | 186 | | 1991 | 177 | | 1990 | 180 | | 1989 | 191 | | 1988 | 200 | | 1987 | 208 | | 1986 | 213 | | 1985 | 214 | | 1984 | 208 | | 1983 | 205 | | 1982 | 214 | | 1981 | 217 | | 1980 | 212 | | 1979 | 201 | | 1978 | 187 | | 1977 | 175 | | 1976 | 176 | | 1975 | 183 |
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