Year	Number
2010	0.7713478132
2011	0.8154319151
2012	0.8595160171
2013	0.903600119
2014	0.8934096995
2015	0.9307497769
2016	0.9010711098
2017	0.9010711098
2018	0.9010711098
2019	0.9010711098
2020	0.9010711098