Year	% of population
2001	18.9
2002	18.6
2003	17.3
2004	16.2
2005	14.6
2006	13.4
2007	12.2
2008	11.3
2009	11.8
2010	12.3
2011	12.5
2012	11.9
2013	11.2
2014	10.4
2015	9.1
2016	7.8
2017	6.4
2018	5.4
2019	5
2020	5.1
2021	5.2
