| Year | Value | | 2021 | 2.1967156656769 | | 2020 | -4.5959362069801 | | 2019 | 3.326841648687 | | 2018 | 3.1519441142989 | | 2017 | 2.701184654825 | | 2016 | 5.905719871293 | | 2015 | 5.791885283322 | | 2014 | 5.9341819495899 | | 2013 | 5.6032862194728 | | 2012 | 0.42097056016863 | | 2011 | 1.0818887896427 | | 2010 | 2.3940148498094 | | 2009 | 1.3812881668637 | | 2008 | 11.285457914411 | | 2007 | -3.2193329171498 | | 2006 | 6.3099942513503 | | 2005 | 5.3360154428882 | | 2004 | 5.3814013913225 | | 2003 | 0.078182271845577 | | 2002 | 0.29758841176815 | | 2001 | 0.88157663192648 | | 2000 | 16.060521103474 | | 1999 | 4.8855971089366 | | 1998 | 0.35800463352371 | | 1997 | -4.5048562156918 | | 1996 | -3.6101184247207 | | 1995 | 7.531798426358 | | 1994 | 6.0344904821687 |
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