Year	% of population
2001	4.9
2002	6
2003	7.4
2004	8.6
2005	8.9
2006	8.8
2007	8.3
2008	7.4
2009	6.1
2010	5.4
2011	4.8
2012	4.5
2013	4.4
2014	4.4
2015	4.3
2016	4.2
2017	4.2
2018	4.1
2019	4.1
2020	4.1
2021	4.1