Year	% of population
2003	10
2004	9.7
2005	9.6
2006	10.1
2007	10.1
2008	10.2
2009	9.8
2010	9.2
2011	7.9
2012	9.3
2013	7.9
2014	9.2
2015	8.8
2016	10.1
2017	8.8