Year	Number
2006	0.641824901103973
2007	0.43947970867157
2008	0.298803210258484
2009	0.311296105384827
2010	0.273786127567291
2011	0.26718533039093
2012	0.246398240327835
2013	0.252466678619385
2014	0.212399378418922
2015	0.21929794549942
2016	0.223960906267166
2017	0.233241319656372
2018	0.23016220331192
2019	0.250075668096542
2020	0.247393816709518
2021	0.248921230435371
2022	0.248592063784599