Year	Number
1996	-1.63046932220459
1998	-1.52733862400055
2000	-1.60150170326233
2002	-1.63334381580353
2003	-1.48285591602325
2004	-1.52091634273529
2005	-1.46479499340057
2006	-1.31127274036407
2007	-1.3751335144043
2008	-1.37856388092041
2009	-1.23628926277161
2010	-1.27295327186584
2011	-1.27705323696136
2012	-1.30477690696716
2013	-1.29079580307007
2014	-1.07478952407837
2015	-1.030846118927
2016	-1.00386559963226
2017	-1.03973150253296
2018	-1.00093221664429
2019	-1.02519094944
2020	-0.95099937915802
2021	-0.984480023384094
2022	-1.02190458774567