Year	Number
1996	-0.27884715795517
1998	-0.504802107810974
2000	-1.12727546691895
2002	-1.15675950050354
2003	-1.18886756896973
2004	-1.25356316566467
2005	-1.31461668014526
2006	-1.3729487657547
2007	-1.40475797653198
2008	-1.34883809089661
2009	-1.35787522792816
2010	-1.37328672409058
2011	-1.42562651634216
2012	-1.38180339336395
2013	-1.41966700553894
2014	-1.40436673164368
2015	-1.33761739730835
2016	-1.2884407043457
2017	-1.29848527908325
2018	-1.24600064754486
2019	-1.27119028568268
2020	-1.2879923582077
2021	-1.25355005264282
2022	-1.2551394701004