Year	Number
1996	0.480888694524765
1998	0.453148931264877
2000	0.461006760597229
2002	0.427986711263657
2003	0.395839601755142
2004	0.365187674760818
2005	0.287387371063232
2006	0.315462857484818
2007	0.32002717256546
2008	0.306297153234482
2009	0.315882474184036
2010	0.304613053798676
2011	0.307621657848358
2012	0.300836741924286
2013	0.308940380811691
2014	0.341326415538788
2015	0.228912457823753
2016	0.22597847878933
2017	0.224251568317413
2018	0.202491328120232
2019	0.20344865322113
2020	0.204005151987076
2021	0.240289986133575
2022	0.246608749032021