Year	Number
1996	-0.548815250396729
1998	-0.37074676156044
2000	-0.726261258125305
2002	-1.03259038925171
2003	-1.1155811548233
2004	-1.36047637462616
2005	-1.86383938789368
2006	-1.50709736347198
2007	-1.54307162761688
2008	-1.50833129882813
2009	-1.54677140712738
2010	-1.42578947544098
2011	-1.40473687648773
2012	-1.37908899784088
2013	-1.62785887718201
2014	-0.895563185214996
2015	-1.20977377891541
2016	-1.25973296165466
2017	-1.253626704216
2018	-0.985568642616272
2019	-0.928613364696503
2020	-0.915807783603668
2021	-1.03663277626038
2022	-1.09237110614777