| Year | Value | | 2021 | 2.9222914586547 | | 2020 | -4.4811439711314 | | 2019 | 6.5839951664232 | | 2018 | 5.1201288021684 | | 2017 | 2.3833917973796 | | 2016 | 5.3164449682613 | | 2015 | 4.3890490243273 | | 2014 | 3.8500624167196 | | 2013 | 4.6056253539343 | | 2012 | -1.7764524033098 | | 2011 | 0.41093910322655 | | 2010 | 0.6088847457109 | | 2009 | -6.0899896819635 | | 2008 | 1.2978943907492 | | 2007 | -1.3689776220907 | | 2006 | 2.560823032916 | | 2005 | 3.0762057910622 | | 2004 | 5.8124382794289 | | 2003 | 4.7095742135107 | | 2002 | 7.8715036659553 | | 2001 | 5.7222279834065 | | 2000 | 4.1541654608656 | | 1999 | 1.5249594946905 | | 1998 | 5.5530205579218 | | 1997 | 3.2262384983304 | | 1996 | -1.3355520369709 | | 1995 | -2.6061187353709 | | 1994 | 3.2528902465383 |
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