Year	% of population
2001	15.7
2002	13.7
2003	12.3
2004	11.1
2005	10.3
2006	10.4
2007	11.3
2008	12.8
2009	14
2010	15.4
2011	16.2
2012	16.1
2013	15.9
2014	16.2
2015	16.1
2016	15.8
2017	15.3
2018	15.3
2019	14.9
2020	13.5
2021	13.1