Year Number 1996 -0.602832019329071 1998 -0.610585570335388 2000 -0.641752243041992 2002 -0.766993641853333 2003 -0.637721121311188 2004 -0.556896567344666 2005 -0.601215302944183 2006 -0.625979781150818 2007 -0.57259863615036 2008 -0.630675971508026 2009 -0.633366286754608 2010 -0.631919384002686 2011 -0.609958648681641 2012 -0.676629722118378 2013 -0.65251749753952 2014 -0.602058231830597 2015 -0.505210995674133 2016 -0.502611756324768 2017 -0.433582544326782 2018 -0.372491270303726 2019 -0.375260800123215 2020 -0.236916333436966 2021 -0.404661357402802 2022 -0.429956316947937