Year	Number
1996	0.47480720281601
1998	0.435220897197723
2000	0.453906059265137
2002	0.436297506093979
2003	0.349641561508179
2004	0.330648332834244
2005	0.332869827747345
2006	0.28942021727562
2007	0.280838459730148
2008	0.285063475370407
2009	0.268250793218613
2010	0.260921776294708
2011	0.260776847600937
2012	0.243881538510323
2013	0.242341712117195
2014	0.207291051745415
2015	0.213819772005081
2016	0.219450056552887
2017	0.228199601173401
2018	0.225225403904915
2019	0.243729904294014
2020	0.247393816709518
2021	0.248921230435371
2022	0.248592063784599