Year	Number
1996	0.480888694524765
1998	0.453148931264877
2000	0.461006760597229
2002	0.427986711263657
2003	0.395839601755142
2004	0.365187674760818
2005	0.325725704431534
2006	0.390265733003616
2007	0.389907509088516
2008	0.4012451171875
2009	0.426269233226776
2010	0.430662959814072
2011	0.418170005083084
2012	0.433321326971054
2013	0.442143976688385
2014	0.42502698302269
2015	0.273373037576675
2016	0.269056439399719
2017	0.265884310007095
2018	0.264159142971039
2019	0.26157134771347
2020	0.252231359481812
2021	0.273426532745361
2022	0.284191817045212