| Year | Value | | 2022 | 694 | | 2021 | 566 | | 2020 | 545 | | 2019 | 515 | | 2018 | 485 | | 2017 | 458 | | 2016 | 438 | | 2015 | 421 | | 2014 | 404 | | 2013 | 394 | | 2012 | 386 | | 2011 | 384 | | 2010 | 397 | | 2009 | 390 | | 2008 | 391 | | 2007 | 383 | | 2006 | 382 | | 2005 | 380 | | 2004 | 380 | | 2003 | 380 | | 2002 | 380 | | 2001 | 357 | | 2000 | 337 | | 1999 | 316 | | 1998 | 300 | | 1997 | 363 | | 1996 | 429 | | 1995 | 419 | | 1994 | 417 | | 1993 | 409 | | 1992 | 393 | | 1991 | 381 | | 1990 | 365 | | 1989 | 353 | | 1988 | 338 | | 1987 | 327 | | 1986 | 308 | | 1985 | 302 | | 1984 | 295 | | 1983 | 291 | | 1982 | 287 | | 1981 | 282 | | 1980 | 273 | | 1979 | 263 | | 1978 | 248 | | 1977 | 245 | | 1976 | 245 | | 1975 | 240 | | 1974 | 232 | | 1973 | 223 | | 1972 | 214 | | 1971 | 203 | | 1970 | 194 | | 1969 | 189 | | 1968 | 189 | | 1967 | 189 | | 1966 | 185 | | 1965 | 181 | | 1964 | 177 | | 1963 | 173 | | 1962 | 169 | | 1961 | 168 | | 1960 | 168 |
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