Year	Number
1996	-1.70883572101593
1998	-1.67008805274963
2000	-1.63161826133728
2002	-1.32037007808685
2003	-1.55695199966431
2004	-1.53163993358612
2005	-1.64995002746582
2006	-1.37605774402618
2007	-1.42486453056335
2008	-1.44502377510071
2009	-1.27007055282593
2010	-1.33723092079163
2011	-1.30141592025757
2012	-1.243647813797
2013	-1.28314566612244
2014	-1.16957986354828
2015	-1.2331770658493
2016	-1.28213763237
2017	-1.12548971176147
2018	-1.13887703418732
2019	-1.17616295814514
2020	-1.08891248703003
2021	-1.21970641613007
2022	-1.26452505588531