Year	Number
1996	0.409431099891663
1998	0.345668405294418
2000	0.342506408691406
2002	0.316015273332596
2003	0.301584661006927
2004	0.293032377958298
2005	0.278116136789322
2006	0.252854287624359
2007	0.244294539093971
2008	0.241307944059372
2009	0.241539120674133
2010	0.239330947399139
2011	0.243252038955688
2012	0.21966552734375
2013	0.225787356495857
2014	0.192247405648232
2015	0.196433380246162
2016	0.203295975923538
2017	0.201735362410545
2018	0.202375143766403
2019	0.20880027115345
2020	0.208693087100983
2021	0.212381526827812
2022	0.21676841378212