Year	% of population
1995	19
2000	17.7
2003	15.9
2004	15.8
2005	16.7
2006	16.8
2007	16.4
2008	15
2009	15.6
2010	17.2
2011	19.6
2012	21.1
2013	20.2
2014	20.2
2015	20.7
2016	19.3
2017	18.5
2018	17
2019	16.8
2020	17.7
2021	16.7