| Year | Value | | 2021 | 7.4252035476414 | | 2020 | -6.187618644002 | | 2019 | 7.9509574633088 | | 2018 | 6.8902176431822 | | 2017 | 16.868787635422 | | 2016 | -1.9619068721306 | | 2015 | 0.96985086291095 | | 2014 | 7.3760022528105 | | 2013 | 1.9337934350376 | | 2012 | 4.7474906508321 | | 2011 | 6.0257152020515 | | 2010 | 6.3088254383927 | | 2009 | 5.3393394064863 | | 2008 | 4.4612906739791 | | 2007 | 2.9256231851956 | | 2006 | 2.4408554281689 | | 2005 | 3.356221326525 | | 2004 | 2.8131111696376 | | 2003 | 2.9543544286671 | | 2002 | 0.8058668983596 |
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