Year	Number
1996	0.340506970882416
1998	0.324012994766235
2000	0.346905559301376
2002	0.352838128805161
2003	0.326896071434021
2004	0.328975260257721
2005	0.294445633888245
2006	0.300743192434311
2007	0.308770656585693
2008	0.303065836429596
2009	0.309388428926468
2010	0.295142114162445
2011	0.288356453180313
2012	0.296368002891541
2013	0.312376916408539
2014	0.316561937332153
2015	0.313768744468689
2016	0.309745103120804
2017	0.327944248914719
2018	0.327886164188385
2019	0.326451301574707
2020	0.261285066604614
2021	0.28137943148613
2022	0.290792316198349