Year	% of population
2001	17.3
2002	16.4
2003	15
2004	13.7
2005	11.9
2006	10.6
2007	10.2
2008	10.6
2009	10.1
2010	9.6
2011	8.7
2012	8.5
2013	8
2014	7.4
2015	6.9
2016	6.8
2017	6.8
2018	6.5
2019	6
2020	5.6
2021	5.2