Year	% of population
2000	14
2001	14.6
2002	15.5
2003	16.6
2004	17.6
2005	18.2
2006	18.1
2007	17
2008	15.2
2009	13.2
2010	11.7
2011	11
2012	11
2013	11.1
2014	11.1
2015	10.8
2016	10.5
2017	10.3