Year	% of population
2001	9.3
2002	9.5
2003	9.8
2004	10.1
2005	10.1
2006	9.9
2007	9.8
2008	9.6
2009	8.7
2010	8.1
2011	7.9
2012	8
2013	7.9
2014	7.7
2015	7.5
2016	7.3
2017	7
2018	6.5
2019	5.9
2020	5
2021	4.8