Year	% of population
2000	0.662897750446111
2001	0.657883747343986
2002	0.652870407292169
2003	0.647858528133548
2004	0.642846463342144
2005	0.637821494724949
2006	0.632783197836514
2007	0.627731268392044
2008	0.622666195018616
2009	0.617586773686045
2010	0.61249174965504
2011	0.607382570496938
2012	0.602258011225002
2013	0.597116757673035
2014	0.591960259682872
2015	0.59183937803841
2016	0.591702905078332
2017	0.5915518016025
2018	0.591386004105555