Year	% of population
2001	6.3
2002	6.4
2003	7
2004	7.3
2005	7.2
2006	6.2
2007	5
2008	4.2
2009	3.7
2010	3.1
2011	2.6
2012	2.5
2013	2.5
2014	2.5
2015	2.5
2016	2.5
2017	2.5
2018	2.5
2019	2.5
2020	2.5
2021	2.5