Year	Number
1996	-1.57920348644257
1998	-1.41147303581238
2000	-1.56632399559021
2002	-1.50847780704498
2003	-1.30690324306488
2004	-1.34934079647064
2005	-1.19444441795349
2006	-1.22213447093964
2007	-1.24603569507599
2008	-1.31189203262329
2009	-1.29202568531036
2010	-1.3271712064743
2011	-1.32878935337067
2012	-1.27765655517578
2013	-1.21110332012177
2014	-1.11219108104706
2015	-1.13547873497009
2016	-1.15416264533997
2017	-1.12050437927246
2018	-1.14144146442413
2019	-1.09754633903503
2020	-1.09179103374481
2021	-0.955476522445679
2022	-0.930956423282623