| Year | Value | | 2021 | 5.5448165067488 | | 2020 | -9.9668635575803 | | 2019 | 3.9625455896647 | | 2018 | 0.30138133630213 | | 2017 | 0.20873435178399 | | 2016 | 2.4072236631004 | | 2015 | 3.9470112013784 | | 2014 | 0.90363156449322 | | 2013 | 0.08257552330646 | | 2012 | 1.011032249526 | | 2011 | 3.3718770845407 | | 2010 | 1.6139277783746 | | 2009 | -3.9787191540443 | | 2008 | -1.6596164590417 | | 2007 | 0.55157031677184 | | 2006 | 3.6775495328844 | | 2005 | 3.9845561314837 | | 2004 | -1.1722709579147 | | 2003 | 0.18779730544946 | | 2002 | 0.74221346312598 | | 2001 | 0.81266908646091 | | 2000 | 0.47802043371246 | | 1999 | 0.5575218944731 | | 1998 | 3.5826949904748 | | 1997 | 2.7907817884323 | | 1996 | 0.30069765335287 | | 1995 | 6.9572383646343 | | 1994 | 6.7916723805254 | | 1993 | 8.7796392319171 | | 1992 | 8.183743799935 | | 1991 | 2.0183706959551 |
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