Year	Number
1996	-1.90854012966156
1998	-2.03930115699768
2000	-2.03141713142395
2002	-1.43342101573944
2003	-1.1775711774826
2004	-1.20303392410278
2005	-1.12542963027954
2006	-1.11029398441315
2007	-1.05765390396118
2008	-1.16890180110931
2009	-1.37549519538879
2010	-1.40446734428406
2011	-1.33597695827484
2012	-1.26743006706238
2013	-1.24006843566895
2014	-1.13543999195099
2015	-1.11755669116974
2016	-1.03778803348541
2017	-0.99081426858902
2018	-1.00705206394196
2019	-1.00657486915588
2020	-1.07768857479095
2021	-1.56788992881775
2022	-1.75158727169037