Year Number 1996 -0.782561779022217 1998 -0.899157166481018 2000 -0.878509700298309 2002 -0.72459751367569 2003 -0.744711637496948 2004 -0.677577555179596 2005 -0.500253260135651 2006 -0.47920623421669 2007 -0.42621174454689 2008 -0.537264764308929 2009 -0.680893421173096 2010 -0.676808714866638 2011 -0.648009061813354 2012 -0.831212103366852 2013 -0.792035818099976 2014 -0.750901997089386 2015 -0.704286694526672 2016 -0.67736828327179 2017 -0.666013300418854 2018 -0.711567580699921 2019 -0.705255508422852 2020 -0.80155736207962 2021 -0.888018608093262 2022 -0.879449665546417