| Year | Value | | 2021 | 10.34242044 | | 2020 | 6.1 | | 2019 | 6.017815092 | | 2018 | 6 | | 2017 | 5.9 | | 2016 | 5.9 | | 2015 | 5.8 | | 2014 | 5.4 | | 2013 | 5.1 | | 2012 | 4.8 | | 2011 | 4.6 | | 2010 | 4.3 | | 2009 | 4.1 | | 2008 | 3.88 | | 2007 | 3.671965351 | | 2006 | 2.529363038 | | 2005 | 1.742205503 | | 2004 | 0.71997068 | | 2003 | 0.46484984 | | 2002 | 0.384093505 | | 2001 | 0.237945087 | | 2000 | 0.163714063 | | 1999 | 0.10554394 | | 1998 | 0.065289465 | | 1997 | 0.010319341 | | 1996 | 0.004625948 | | 1995 | 0.002863471 |
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