Year	Number
1996	-1.13253033161163
1998	-1.30651867389679
2000	-1.3412059545517
2002	-1.7388927936554
2003	-1.77545630931854
2004	-1.55103635787964
2005	-1.65545511245728
2006	-1.73277974128723
2007	-1.71849822998047
2008	-1.70953750610352
2009	-1.69936954975128
2010	-1.67684030532837
2011	-1.67850601673126
2012	-1.64357113838196
2013	-1.64945232868195
2014	-1.73322033882141
2015	-1.75351190567017
2016	-1.75913119316101
2017	-1.75141417980194
2018	-1.75023281574249
2019	-1.81557559967041
2020	-1.79262125492096
2021	-1.6781542301178
2022	-1.65662670135498