Year	Number
1996	-1.14967966079712
1998	-1.10067796707153
2000	-1.15839385986328
2002	-1.38285386562347
2003	-1.41546761989594
2004	-1.54980719089508
2005	-1.56691956520081
2006	-1.51765394210815
2007	-1.40627419948578
2008	-1.40183234214783
2009	-1.38866555690765
2010	-1.52704012393951
2011	-1.51512265205383
2012	-1.12933874130249
2013	-1.13601219654083
2014	-0.52522075176239
2015	-0.600480258464813
2016	-0.913617134094238
2017	-1.01185739040375
2018	-1.08982193470001
2019	-1.01762771606445
2020	-1.02349519729614
2021	-0.962062120437622
2022	-1.1583536863327