| Year | Value | | 2017 | 2.004048698 | | 2016 | 1.88 | | 2015 | 1.76 | | 2014 | 1.63 | | 2013 | 1.5 | | 2012 | 1.3767 | | 2011 | 1.25 | | 2009 | 1.160610542 | | 2008 | 1.142687372 | | 2007 | 1.122235622 | | 2006 | 1.100216368 | | 2005 | 1.077327839 | | 2004 | 1.053454744 | | 2003 | 0.376198003 | | 2002 | 0.115614213 | | 2001 | 0.079039179 | | 2000 | 0.02 | | 1999 | 0.013910394 | | 1998 | 0.00716442 | | 1997 | 0.002948713 | | 1996 | 0.00150955 |
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