Year	% of population
2004	12.2
2005	11.6
2006	11.5
2007	12.3
2008	11.3
2009	12.7
2010	13.6
2011	13.5
2012	14.5
2013	14.5
2014	14.3
2015	13.9
2016	13.3
2017	13.3
2018	12
2019	12.4
2020	11.7
2021	12.1
2022	12.7