Year	% of population
2001	8.1
2002	7.4
2003	7
2004	7
2005	6.7
2006	6.4
2007	5.9
2008	5.6
2009	5.1
2010	4.3
2011	3.7
2012	3.1
2013	2.9
2014	2.7
2015	2.6
2016	2.6
2017	2.6
2018	2.5
2019	2.5
2020	2.5
2021	2.5