Year	Number
1996	-0.969682216644287
1998	-0.773010969161987
2000	-1.21208262443542
2002	-1.44908678531647
2003	-1.54172050952911
2004	-1.59711492061615
2005	-1.40646660327911
2006	-1.44298279285431
2007	-1.06323993206024
2008	-1.0467883348465
2009	-1.0752512216568
2010	-1.05408024787903
2011	-1.09738862514496
2012	-0.85661906003952
2013	-0.893825352191925
2014	-0.892129957675934
2015	-0.844025909900665
2016	-0.88687801361084
2017	-0.858938634395599
2018	-0.926946818828583
2019	-1.01699352264404
2020	-1.00367724895477
2021	-0.98586094379425
2022	-1.0755273103714