| Year | Value | | 2021 | 29.754785021147 | | 2020 | 25.4228694116 | | 2019 | 21.340617210599 | | 2018 | 18.459294070809 | | 2017 | 15.987201635932 | | 2016 | 13.686364060249 | | 2015 | 10.70999364167 | | 2014 | 8.6234405200188 | | 2013 | 5.7991486893152 | | 2012 | 4.658948212418 | | 2011 | 3.7656449348417 | | 2010 | 3.0992136194863 | | 2009 | 2.3929366700873 | | 2008 | 1.8909288189688 | | 2007 | 1.787031737672 | | 2006 | 1.066035933651 | | 2005 | 0.74992678957325 | | 2004 | 0.53441726176141 | | 2003 | 0.35155092474525 | | 2002 | 0.2332327708109 | | 2001 | 0.14407895323758 | | 2000 | 0.099637597062036 | | 1999 | 0.058291067023342 | | 1998 | 0.021423482891026 | | 1997 | 0.0086571571057105 | | 1995 | 0.00034320016491224 | | 1994 | 0.00010337225841935 |
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