Year	Number
1996	0.373912304639816
1998	0.345668405294418
2000	0.313380271196365
2002	0.286041706800461
2003	0.282846570014954
2004	0.278957605361938
2005	0.270123898983002
2006	0.245767414569855
2007	0.239249795675278
2008	0.241307944059372
2009	0.241539120674133
2010	0.239330947399139
2011	0.238522350788116
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