| Year | Value | | 2021 | 6.6740447983828 | | 2020 | 1.2618390668312 | | 2019 | 3.7462543202878 | | 2018 | 3.3776765059955 | | 2017 | 8.0439006993402 | | 2016 | 0.43113542782618 | | 2015 | -5.1668611232358 | | 2014 | -7.9406586273696 | | 2013 | 0.43276015859668 | | 2012 | 9.7600188070218 | | 2011 | 8.1419141168526 | | 2010 | 9.795916330167 | | 2009 | -24.345952803332 | | 2008 | 4.6819602245824 | | 2007 | 16.414782571888 | | 2006 | 9.932285366696 | | 2005 | 9.552150279806 | | 2004 | 16.252931322733 | | 2003 | 11.151961199898 | | 2002 | 5.9651391663787 | | 2001 | 9.4460217711934 | | 2000 | 0.9160217288935 | | 1999 | 3.3626894552907 | | 1998 | 1.0662396214735 | | 1997 | 0.28341231706833 | | 1996 | -11.862059137199 |
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