Year	Number
2004	0.42519822716713
2005	0.369224309921265
2006	0.362917214632034
2007	0.331106036901474
2008	0.332146733999252
2009	0.370833456516266
2010	0.349873960018158
2011	0.335981905460358
2012	0.301696002483368
2013	0.324702829122543
2014	0.259938985109329
2015	0.270398736000061
2016	0.272953003644943
2017	0.284396678209305
2018	0.274537473917007
2019	0.305256575345993
2020	0.307376354932785
2021	0.320550739765167
2022	0.307975441217422