| Year | Value | | 2022 | 0.909 | | 2021 | 0.794 | | 2020 | 1.206 | | 2019 | 1.502 | | 2018 | 1.239 | | 2017 | 1.622 | | 2016 | 1.591 | | 2015 | 1.781 | | 2014 | 1.451 | | 2013 | 1.894 | | 2012 | 2.19 | | 2011 | 2.677 | | 2010 | 2.972 | | 2009 | 3.024 | | 2008 | 2.097 | | 2007 | 2.749 | | 2006 | 4.26 | | 2005 | 5.633 | | 2004 | 6.374 | | 2003 | 6.378 | | 2002 | 6.845 | | 2001 | 7.366 | | 2000 | 8.539 | | 1999 | 11.14 |
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