Year	Number
1996	0.350509405136108
1998	0.327276676893234
2000	0.291758239269257
2002	0.332443028688431
2003	0.31847807765007
2004	0.301842093467712
2005	0.252828240394592
2006	0.271784961223602
2007	0.272402256727219
2008	0.212972044944763
2009	0.210192918777466
2010	0.20214432477951
2011	0.203772380948067
2012	0.207406997680664
2013	0.205795213580132
2014	0.229263111948967
2015	0.225333109498024
2016	0.305006235837936
2017	0.305364817380905
2018	0.303494453430176
2019	0.303162574768066
2020	0.332086175680161
2021	0.339030981063843
2022	0.318909525871277