Year Number 1996 -0.925459146499634 1998 -0.423062264919281 2000 -0.200209870934486 2002 -0.0583082623779774 2003 -0.11687808483839 2004 -0.214082449674606 2005 -0.445820868015289 2006 -0.636888444423676 2007 -0.729851603507996 2008 -0.804012358188629 2009 -0.686627805233002 2010 -0.726463437080383 2011 -0.667768597602844 2012 -0.662454187870026 2013 -0.714223802089691 2014 -0.853918790817261 2015 -0.801780104637146 2016 -0.633718132972717 2017 -0.806073427200317 2018 -0.673981010913849 2019 -0.843628823757172 2020 -0.791369318962097 2021 -0.688360929489136 2022 -0.691959738731384