Year	Number
1996	0.613030731678009
1998	0.575733542442322
2000	0.595203697681427
2002	0.518141508102417
2003	0.412701427936554
2004	0.37369167804718
2005	0.369224309921265
2006	0.362917214632034
2007	0.321909368038177
2008	0.31868052482605
2009	0.314036637544632
2010	0.291736155748367
2011	0.285885632038116
2012	0.258637070655823
2013	0.268644094467163
2014	0.212399378418922
2015	0.21929794549942
2016	0.228173807263374
2017	0.233241319656372
2018	0.247710168361664
2019	0.250075668096542
2020	0.247393816709518
2021	0.248921230435371
2022	0.248592063784599