| Year | Value | | 2024 | 311 | | 2023 | 290 | | 2022 | 268 | | 2021 | 243 | | 2020 | 226 | | 2019 | 216 | | 2018 | 207 | | 2017 | 200 | | 2016 | 190 | | 2015 | 183 | | 2014 | 190 | | 2013 | 195 | | 2012 | 193 | | 2011 | 189 | | 2010 | 183 | | 2009 | 172 | | 2008 | 157 | | 2007 | 138 | | 2006 | 124 | | 2005 | 123 | | 2004 | 130 | | 2003 | 137 | | 2002 | 142 | | 2001 | 150 | | 2000 | 160 | | 1999 | 160 | | 1998 | 158 | | 1997 | 160 | | 1996 | 155 | | 1995 | 148 | | 1994 | 148 | | 1993 | 146 | | 1992 | 138 | | 1991 | 133 | | 1990 | 129 | | 1989 | 125 | | 1988 | 124 | | 1987 | 125 | | 1986 | 120 | | 1985 | 115 | | 1984 | 120 | | 1983 | 119 | | 1982 | 111 | | 1981 | 102 | | 1980 | 92 | | 1979 | 82 | | 1978 | 79 | | 1977 | 81 | | 1976 | 80 | | 1975 | 77 |
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