Year	% of population
2001	3.1
2002	3.1
2003	3
2004	2.8
2005	2.8
2006	3.2
2007	3.4
2008	3.5
2009	4.3
2010	5.4
2011	6
2012	6
2013	5.8
2014	6.7
2015	7.3
2016	7.9
2017	7.9
2018	7.7
2019	7.4
2020	5.6
2021	4.6