Year	Number
1996	-1.38199138641357
1998	-1.31434643268585
2000	-1.28874289989471
2002	-1.34433853626251
2003	-1.19470548629761
2004	-1.15032112598419
2005	-1.15101563930511
2006	-0.992507755756378
2007	-0.994199395179749
2008	-0.944533824920654
2009	-0.914634764194489
2010	-0.947139799594879
2011	-0.862535297870636
2012	-0.867620050907135
2013	-0.867795407772064
2014	-0.935593962669373
2015	-0.880601048469543
2016	-0.8023841381073
2017	-0.80730813741684
2018	-0.796907842159271
2019	-0.804334580898285
2020	-0.793761193752289
2021	-0.839913308620453
2022	-0.828648924827576