Year	Number
1996	0.320348232984543
1998	0.296366184949875
2000	0.262675374746323
2002	0.281024992465973
2003	0.268896847963333
2004	0.267506331205368
2005	0.276429831981659
2006	0.27293998003006
2007	0.267737329006195
2008	0.259430557489395
2009	0.256279051303864
2010	0.249384567141533
2011	0.24323970079422
2012	0.244329899549484
2013	0.244014948606491
2014	0.266792684793472
2015	0.272341579198837
2016	0.407818496227264
2017	0.40481886267662
2018	0.411615967750549
2019	0.421195656061172
2020	0.344202011823654
2021	0.351070791482925
2022	0.322908997535706