| Year | Value | | 2017 | 38.70116262 | | 2016 | 29.78777936 | | 2015 | 19.2824418 | | 2014 | 16.8 | | 2013 | 14 | | 2012 | 12.5 | | 2011 | 10 | | 2010 | 7 | | 2009 | 5.6 | | 2008 | 4.6 | | 2007 | 3.95 | | 2006 | 3.795590214 | | 2005 | 3.878702398 | | 2004 | 3.599776814 | | 2003 | 2.569750367 | | 2002 | 2.335444575 | | 2001 | 1.706614078 | | 2000 | 1.534271796 | | 1999 | 0.966071567 | | 1996 | 0.037059432 |
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