Year	% of population
2001	20.6
2002	22.8
2003	23.8
2004	23.2
2005	19.4
2006	16.6
2007	16.4
2008	16.2
2009	15.5
2010	13.5
2011	11.7
2012	10.4
2013	9.2
2014	8.4
2015	7.4
2016	6.7
2017	6
2018	5.7
2019	6.3
2020	6.3
2021	6.3