Year	Number
1996	0.47480720281601
1998	0.435220897197723
2000	0.453906059265137
2002	0.436297506093979
2003	0.349641561508179
2004	0.364736646413803
2005	0.384340941905975
2006	0.317671149969101
2007	0.310351073741913
2008	0.3154336810112
2009	0.293007612228394
2010	0.282069832086563
2011	0.310344904661179
2012	0.278807580471039
2013	0.293446391820908
2014	0.236860454082489
2015	0.24198617041111
2016	0.228173807263374
2017	0.237186849117279
2018	0.234690293669701
2019	0.250075668096542
2020	0.247393816709518
2021	0.248921230435371
2022	0.248592063784599