Year Number 1996 -0.481185793876648 1998 -0.257059156894684 2000 -1.39048433303833 2002 -0.858753323554993 2003 -1.55980968475342 2004 -1.70588445663452 2005 -1.17878663539886 2006 -1.63867163658142 2007 -1.60488569736481 2008 -1.77923631668091 2009 -1.7287632226944 2010 -1.65075957775116 2011 -1.39218163490295 2012 -1.18824028968811 2013 -1.08425319194794 2014 -0.713820934295654 2015 -0.854724228382111 2016 -1.37869036197662 2017 -1.18929064273834 2018 -1.09619224071503 2019 -0.928045392036438 2020 -0.778701364994049 2021 -0.984003067016602 2022 -0.712976396083832