Year	Number
1996	-1.60094857215881
1998	-1.72864663600922
2000	-1.73355114459991
2002	-1.60957503318787
2003	-1.55504846572876
2004	-1.69705295562744
2005	-1.5216383934021
2006	-1.23079133033752
2007	-1.21148073673248
2008	-1.38789105415344
2009	-1.40938663482666
2010	-1.4091020822525
2011	-1.48515594005585
2012	-1.48108160495758
2013	-1.45855402946472
2014	-1.28694593906403
2015	-1.30421757698059
2016	-1.41219067573547
2017	-1.46580123901367
2018	-1.49919176101685
2019	-1.3141884803772
2020	-1.25270986557007
2021	-1.18584728240967
2022	-1.1836930513382