Year	% of population
2001	30.5
2002	30
2003	30.1
2004	29.9
2005	28.8
2006	26.8
2007	24.7
2008	21.9
2009	19.3
2010	16
2011	13.4
2012	11.6
2013	10.6
2014	9.3
2015	7.6
2016	6.8
2017	5.9
2018	5.7
2019	5.1
2020	6.6
2021	8