Year	% of population
2001	6.3
2002	5.9
2003	5.6
2004	5.6
2005	5.5
2006	5.8
2007	5.6
2008	5.7
2009	5.5
2010	5.1
2011	4.6
2012	4.4
2013	4.1
2014	4
2015	3.8
2016	3.7
2017	3.6
2018	3.6
2019	4.2
2020	5.3
2021	6.3