| Year | Value | | 2021 | 3.154963413262 | | 2020 | -1.6409753455675 | | 2019 | 2.8591830726007 | | 2018 | 4.2315659790941 | | 2017 | 4.0856979627879 | | 2016 | -5.6613487822176 | | 2015 | -4.5751676075855 | | 2014 | 3.1577179811735 | | 2013 | 0.27077730825604 | | 2012 | 3.7361757836466 | | 2011 | 17.901045857829 | | 2010 | 7.9779896240666 | | 2009 | -4.1827672291296 | | 2008 | 16.33882932575 | | 2007 | 10.5055311071 | | 2006 | 14.391132890168 | | 2005 | 14.919914327191 | | 2004 | 12.850305721082 | | 2003 | 9.8328190252823 | | 2002 | 7.5311706606818 | | 2001 | 10.214540350572 | | 2000 | 9.2163564805414 | | 1999 | 3.0407538599523 | | 1998 | 11.048469979949 | | 1997 | 10.78505182579 | | 1996 | 4.5157812138409 | | 1995 | -9.9586724251652 | | 1994 | -15.347486265481 | | 1993 | -57.178091119311 |
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