Year	% of population
2004	13.5
2005	15.9
2006	12.3
2007	12.4
2008	12.4
2009	12.3
2010	14.1
2011	14.3
2012	15
2013	15
2014	14.9
2015	14.5
2016	13.4
2017	12.8
2018	12.3
2019	12.3
2020	12.6
2021	12.1