| Year | Value | | 2024 | 434 | | 2023 | 461 | | 2022 | 494 | | 2021 | 525 | | 2020 | 548 | | 2019 | 554 | | 2018 | 548 | | 2017 | 536 | | 2016 | 526 | | 2015 | 530 | | 2014 | 551 | | 2013 | 580 | | 2012 | 600 | | 2011 | 601 | | 2010 | 590 | | 2009 | 579 | | 2008 | 579 | | 2007 | 590 | | 2006 | 610 | | 2005 | 636 | | 2004 | 663 | | 2003 | 690 | | 2002 | 719 | | 2001 | 754 | | 2000 | 795 | | 1999 | 827 | | 1998 | 841 | | 1997 | 843 | | 1996 | 834 | | 1995 | 809 | | 1994 | 762 | | 1993 | 710 | | 1992 | 667 | | 1991 | 633 | | 1990 | 607 | | 1989 | 594 | | 1988 | 585 | | 1987 | 568 | | 1986 | 544 | | 1985 | 516 | | 1984 | 487 | | 1983 | 463 | | 1982 | 444 | | 1981 | 427 | | 1980 | 421 | | 1979 | 417 | | 1978 | 402 | | 1977 | 380 | | 1976 | 358 | | 1975 | 344 |
|