Year	Number
1996	-0.912984549999237
1998	-0.954480051994324
2000	-0.942260086536407
2002	-1.09348249435425
2003	-1.13356590270996
2004	-1.47985637187958
2005	-1.22202289104462
2006	-0.862635135650635
2007	-0.837894082069397
2008	-0.778468251228333
2009	-0.938361287117004
2010	-1.02823603153229
2011	-1.05570805072784
2012	-0.946483671665192
2013	-0.940709590911865
2014	-1.08275556564331
2015	-1.20612668991089
2016	-1.25848579406738
2017	-1.35315918922424
2018	-1.30229508876801
2019	-1.3158164024353
2020	-1.25603675842285
2021	-1.33931851387024
2022	-1.31438434123993