| Year | Value | | 2020 | 0.79968855765627 | | 2019 | 0.97866687448235 | | 2018 | 0.91642628659705 | | 2017 | 0.92038283508102 | | 2016 | 0.89801616354878 | | 2015 | 0.92228302458458 | | 2014 | 0.92927233887068 | | 2013 | 0.93063112797332 | | 2012 | 0.92566091263501 | | 2011 | 0.92820104983251 | | 2010 | 0.93253801562631 | | 2009 | 0.93163335968932 | | 2008 | 1.1782353422 | | 2007 | 1.19085098956 | | 2006 | 1.2029446581551 | | 2005 | 1.1775359566302 | | 2004 | 1.1866755475933 | | 2003 | 1.1486589883329 | | 2002 | 1.3330206400485 | | 2001 | 1.3580654702647 | | 2000 | 1.3588171554731 | | 1999 | 1.3673959055258 | | 1998 | 1.3899322180348 | | 1997 | 1.370900797394 | | 1996 | 1.4629567168 | | 1995 | 1.3969449421483 | | 1994 | 1.4047954096102 | | 1993 | 1.2345039882443 | | 1992 | 1.3041060767787 | | 1991 | 1.2461083452265 |
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