Year	Number
1996	-1.6624231338501
1998	-1.6014848947525
2000	-1.41228187084198
2002	-1.50260782241821
2003	-1.49027299880981
2004	-1.23842835426331
2005	-1.24252092838287
2006	-1.11087679862976
2007	-1.28052830696106
2008	-1.13556611537933
2009	-1.06673920154572
2010	-1.12470984458923
2011	-1.08492064476013
2012	-1.30940592288971
2013	-1.07022106647491
2014	-1.15071046352386
2015	-1.23677468299866
2016	-1.48354923725128
2017	-1.3824896812439
2018	-1.44970750808716
2019	-1.37477970123291
2020	-1.30227255821228
2021	-1.35740172863007
2022	-1.26284074783325