Year Number 1996 -0.270231127738953 1998 -0.178727999329567 2000 -0.189359664916992 2002 -0.259639918804169 2003 -0.282602161169052 2004 -0.533950924873352 2005 -0.434344530105591 2006 -0.363591104745865 2007 -0.571789562702179 2008 -0.436524838209152 2009 -0.36999648809433 2010 -0.396744579076767 2011 -0.407737106084824 2012 -0.303469598293304 2013 -0.147563919425011 2014 -0.220856681466103 2015 -0.260019838809967 2016 -0.263931721448898 2017 -0.260830879211426 2018 -0.506258010864258 2019 -0.531037092208862 2020 -0.492181956768036 2021 -0.602753639221191 2022 -0.718993604183197