Year	% of population
2001	16.5
2002	15.8
2003	15.5
2004	14.9
2005	13.9
2006	13.2
2007	11.8
2008	10.8
2009	11.5
2010	13
2011	14
2012	13
2013	11.7
2014	10.2
2015	9.1
2016	8.1
2017	7.6
2018	7.1
2019	6.4
2020	5.7
2021	5.3