Year	% of population
2001	31.4
2002	29.6
2003	27.1
2004	24.2
2005	22.7
2006	20.8
2007	20.4
2008	18.6
2009	17.3
2010	14.5
2011	13.2
2012	11.6
2013	10.3
2014	8.1
2015	6.7
2016	5.9
2017	5.6
2018	5.3
2019	5.4
2020	5.2
2021	4.7