| Year | Value | | 2023 | 1,295 | | 2022 | 1,226 | | 2021 | 1,179 | | 2020 | 1,135 | | 2019 | 1,090 | | 2018 | 1,047 | | 2017 | 1,006 | | 2016 | 972 | | 2015 | 939 | | 2014 | 901 | | 2013 | 857 | | 2012 | 819 | | 2011 | 781 | | 2010 | 743 | | 2009 | 710 | | 2008 | 686 | | 2007 | 650 | | 2006 | 593 | | 2005 | 539 | | 2004 | 496 | | 2003 | 465 | | 2002 | 451 | | 2001 | 454 | | 2000 | 451 | | 1999 | 440 | | 1998 | 423 | | 1997 | 405 | | 1996 | 401 | | 1995 | 410 | | 1994 | 415 | | 1993 | 409 | | 1992 | 392 | | 1991 | 378 | | 1990 | 378 | | 1989 | 391 | | 1988 | 408 | | 1987 | 421 | | 1986 | 426 | | 1985 | 415 | | 1984 | 391 | | 1983 | 367 | | 1982 | 344 | | 1981 | 324 | | 1980 | 305 | | 1979 | 286 | | 1978 | 264 | | 1977 | 242 | | 1976 | 220 | | 1975 | 199 | | 1974 | 182 |
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