Year	% of population
2003	16.6
2004	15.1
2005	13.9
2006	14.2
2007	15.7
2008	14.9
2009	14.6
2010	14.1
2011	14.4
2012	16.1
2013	17.3
2014	16.4
2015	15.7
2016	14.5
2017	13.6
2018	13.5
2019	13
2020	14.1
2021	12.8