Year	Number
1996	-1.1732771396637
1998	-1.16668713092804
2000	-1.20162928104401
2002	-1.5061753988266
2003	-1.58485579490662
2004	-1.46017730236053
2005	-1.39128422737122
2006	-1.32642245292664
2007	-1.29074168205261
2008	-1.21558952331543
2009	-1.09506952762604
2010	-1.1893208026886
2011	-1.23770332336426
2012	-1.24063181877136
2013	-1.13521087169647
2014	-1.23922824859619
2015	-1.25839722156525
2016	-1.35417854785919
2017	-1.2592921257019
2018	-1.28550410270691
2019	-1.3468052148819
2020	-1.3464127779007
2021	-1.44135892391205
2022	-1.45903766155243