| Year | Value | | 2021 | 38.91744466 | | 2020 | 32.87 | | 2019 | 27.76 | | 2018 | 23.44 | | 2017 | 19.8 | | 2016 | 18.1 | | 2015 | 12.9 | | 2014 | 11.9 | | 2013 | 6.63 | | 2012 | 5 | | 2011 | 4.5 | | 2010 | 3.7 | | 2009 | 3.1 | | 2008 | 2.5 | | 2007 | 1.8 | | 2006 | 1 | | 2005 | 0.241637326 | | 2004 | 0.199036334 | | 2003 | 0.163877665 | | 2002 | 0.139920289 | | 2001 | 0.129807974 | | 2000 | 0.071039423 | | 1999 | 0.036170407 | | 1998 | 0.003684813 | | 1997 | 0.000751046 |
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