Year	Number
2004	0.410197407007217
2005	0.27973136305809
2006	0.342873007059097
2007	0.381733566522598
2008	0.393487066030502
2009	0.391353219747543
2010	0.388283431529999
2011	0.323667377233505
2012	0.325496852397919
2013	0.318169206380844
2014	0.353842169046402
2015	0.390668779611588
2016	0.384507298469543
2017	0.392347872257233
2018	0.385205060243607
2019	0.391434550285339
2020	0.427005618810654
2021	0.422974407672882
2022	0.400206208229065