Year Number 2004 0.791444957256317 2005 -0.120893590152264 2006 -0.104157447814941 2007 -0.240319490432739 2008 -0.21752493083477 2009 -0.219170406460762 2010 -0.259419351816177 2011 -0.266759753227234 2012 -0.345227032899857 2013 -0.393216013908386 2014 0.0276108961552382 2015 0.00584867876023054 2016 0.0554391071200371 2017 0.0694240033626556 2018 0.0511946864426136 2019 0.386845588684082 2020 0.484758734703064 2021 0.660916447639465 2022 0.651753723621368