| Year | Value | | 2021 | 58.91291568 | | 2020 | 56.42093688 | | 2019 | 54.0343672 | | 2018 | 43.7 | | 2017 | 35.3 | | 2016 | 28.57 | | 2015 | 25.64304231 | | 2014 | 25 | | 2013 | 24.7 | | 2012 | 20.78178258 | | 2011 | 18.13 | | 2010 | 11.04 | | 2009 | 8.94 | | 2008 | 6.85 | | 2007 | 4.1 | | 2006 | 3.696538789 | | 2005 | 3.696961073 | | 2004 | 3.228685073 | | 2003 | 2.437073851 | | 2002 | 1.816203807 | | 2001 | 1.28159005 | | 2000 | 0.926191777 | | 1999 | 0.4707176 | | 1998 | 0.096099605 | | 1997 | 0.088545986 | | 1996 | 0.050399009 | | 1995 | 0.00103175 |
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