| Year | Value | | 2023 | 1,848 | | 2022 | 1,743 | | 2021 | 1,658 | | 2020 | 1,587 | | 2019 | 1,530 | | 2018 | 1,486 | | 2017 | 1,454 | | 2016 | 1,430 | | 2015 | 1,399 | | 2014 | 1,355 | | 2013 | 1,306 | | 2012 | 1,245 | | 2011 | 1,163 | | 2010 | 1,081 | | 2009 | 1,009 | | 2008 | 943 | | 2007 | 872 | | 2006 | 804 | | 2005 | 734 | | 2004 | 660 | | 2003 | 592 | | 2002 | 551 | | 2001 | 536 | | 2000 | 523 | | 1999 | 519 | | 1998 | 525 | | 1997 | 541 | | 1996 | 570 | | 1995 | 591 | | 1994 | 587 | | 1993 | 572 | | 1992 | 553 | | 1991 | 531 | | 1990 | 532 | | 1989 | 553 | | 1988 | 574 | | 1987 | 580 | | 1986 | 562 | | 1985 | 531 | | 1984 | 508 | | 1983 | 489 | | 1982 | 462 | | 1981 | 430 | | 1980 | 399 | | 1979 | 369 | | 1978 | 339 | | 1977 | 315 | | 1976 | 297 | | 1975 | 280 | | 1974 | 267 |
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