Year	% of population
2001	20.8
2002	21.4
2003	20.6
2004	18.6
2005	17.1
2006	15.9
2007	15.3
2008	15.2
2009	15.3
2010	15.1
2011	14.9
2012	14.9
2013	14
2014	13.3
2015	12.1
2016	11.5
2017	10.8
2018	11
2019	13.1
2020	16
2021	18.5