| Year | Value | | 2020 | 0.8772214989445 | | 2019 | 0.88338656459106 | | 2018 | 0.90153951129488 | | 2017 | 0.91922085398501 | | 2016 | 0.93261507285872 | | 2015 | 0.94838950207497 | | 2014 | 0.96254214200869 | | 2013 | 0.97535594251928 | | 2012 | 0.98648266305267 | | 2011 | 0.99875195326785 | | 2010 | 1.0123062967843 | | 2009 | 1.024130572616 | | 2008 | 1.03864280748 | | 2007 | 1.0483128329935 | | 2006 | 1.0608053634319 | | 2005 | 1.0721277068071 | | 2004 | 1.058351355293 | | 2003 | 1.0846091190433 | | 2002 | 1.247325425693 | | 2001 | 1.3266451217753 | | 2000 | 1.3630946748655 | | 1999 | 1.3617134117349 | | 1998 | 1.3966788447261 | | 1997 | 1.4407098149778 | | 1996 | 1.5848031077793 | | 1995 | 1.7073526967611 | | 1994 | 1.1034097671267 | | 1993 | 1.2408192302164 | | 1992 | 1.2541812574108 | | 1991 | 1.2063883895037 | | 1990 | 1.2476495668438 |
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