Year	Number
1996	-0.318770557641983
1998	-0.424850851297379
2000	-0.757242500782013
2002	-0.839923083782196
2003	-0.935435831546783
2004	-1.0071257352829
2005	-1.35831820964813
2006	-1.26054012775421
2007	-1.2986204624176
2008	-1.54632294178009
2009	-1.55316436290741
2010	-1.53839468955994
2011	-1.42085576057434
2012	-1.37375247478485
2013	-1.30818068981171
2014	-1.27943360805511
2015	-1.24870657920837
2016	-1.25799870491028
2017	-1.2821079492569
2018	-1.29790580272675
2019	-1.31977355480194
2020	-1.35572576522827
2021	-1.30481684207916
2022	-1.25461292266846