Year	Number
1996	0.421715974807739
1998	0.381433337926865
2000	0.396205484867096
2002	0.392881572246552
2003	0.330509543418884
2004	0.345351129770279
2005	0.311466783285141
2006	0.316885411739349
2007	0.290890961885452
2008	0.292073458433151
2009	0.282444268465042
2010	0.267576217651367
2011	0.260717630386353
2012	0.233037114143372
2013	0.238264307379723
2014	0.205589711666107
2015	0.208575189113617
2016	0.214360997080803
2017	0.222477972507477
2018	0.2210383862257
2019	0.234910249710083
2020	0.237614139914513
2021	0.239949867129326
2022	0.239937707781792