Year	Number
1996	0.616059839725494
1998	0.563318967819214
2000	0.586516797542572
2002	0.436297506093979
2003	0.349641561508179
2004	0.364736646413803
2005	0.384340941905975
2006	0.317671149969101
2007	0.310351073741913
2008	0.3154336810112
2009	0.293007612228394
2010	0.273786127567291
2011	0.300698131322861
2012	0.246398240327835
2013	0.252466678619385
2014	0.227504342794418
2015	0.21929794549942
2016	0.223960906267166
2017	0.233241319656372
2018	0.23016220331192
2019	0.250075668096542
2020	0.247393816709518
2021	0.248921230435371
2022	0.248592063784599