Year	% of population
2006	15
2007	15.7
2008	15.6
2009	15
2010	15
2011	15.9
2012	14.5
2013	13.8
2014	15.6
2015	14.7
2016	15.5
2017	14.6
2018	16
2019	15.5
2020	14.7