| Year | Value | | 2021 | 32.447262927779 | | 2020 | 27.608998847709 | | 2019 | 23.565050801717 | | 2018 | 20.834101468598 | | 2017 | 18.198017946182 | | 2016 | 15.407431613042 | | 2015 | 11.801172875077 | | 2014 | 9.4678667039814 | | 2013 | 6.7705433261889 | | 2012 | 5.645836878094 | | 2011 | 4.7282924212993 | | 2010 | 4.0252378915906 | | 2009 | 3.1516464592581 | | 2008 | 2.5507532268979 | | 2007 | 2.3527912484504 | | 2006 | 1.5080951286198 | | 2005 | 1.0495550210501 | | 2004 | 0.77764067916704 | | 2003 | 0.5595135927788 | | 2002 | 0.3716236849528 | | 2001 | 0.21626226105285 | | 2000 | 0.14942556222723 | | 1999 | 0.080369699013031 | | 1998 | 0.03844836667487 | | 1997 | 0.01876989814111 | | 1995 | 0.0010354024695029 | | 1994 | 0.00026574706650311 |
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