Year	Number
1996	0.47480720281601
1998	0.435220897197723
2000	0.453906059265137
2002	0.436297506093979
2003	0.349641561508179
2004	0.364736646413803
2005	0.384340941905975
2006	0.376439899206162
2007	0.348420560359955
2008	0.350017130374908
2009	0.30592405796051
2010	0.301820993423462
2011	0.273884326219559
2012	0.254446119070053
2013	0.261302709579468
2014	0.218982502818108
2015	0.223781511187553
2016	0.228173807263374
2017	0.237186849117279
2018	0.234690293669701
2019	0.250075668096542
2020	0.247393816709518
2021	0.248921230435371
2022	0.248592063784599