| Year | Value | | 2021 | 6.7567871244586 | | 2020 | 0.33304331901316 | | 2019 | 4.3476799837678 | | 2018 | 4.2831432307675 | | 2017 | 6.8520077765585 | | 2016 | 7.4009740681554 | | 2015 | 7.2223393280096 | | 2014 | 7.918955958443 | | 2013 | 5.892664350858 | | 2012 | 9.7288088350028 | | 2011 | 4.8706374801159 | | 2010 | 8.2695132111782 | | 2009 | 12.657769344565 | | 2008 | 5.7787986192255 | | 2007 | 26.13361574854 | | 2006 | 16.293422145408 | | 2005 | 8.7852621211521 | | 2004 | 24.516074579129 | | 2003 | -6.8220183743565 | | 2002 | 36.534298374494 | | 2001 | 6.6163026855838 | | 2000 | 0.40252267905352 | | 1999 | 0.72272254378893 | | 1998 | -16.151247809563 | | 1997 | 3.5729345515404 | | 1996 | -10.097788925442 |
|