Year	% of population
2001	14.6
2002	12.5
2003	10.2
2004	8.1
2005	8
2006	8.6
2007	9.1
2008	8.5
2009	8.1
2010	7.4
2011	6.9
2012	6.2
2013	5.9
2014	5.7
2015	5.8
2016	5.5
2017	5.1
2018	4.5
2019	4.5
2020	4.6
2021	4.8