Year	% of population
2001	23.3
2002	22.4
2003	21.1
2004	19.4
2005	19.1
2006	19.2
2007	18.5
2008	17.8
2009	15.8
2010	15.3
2011	14.4
2012	14.7
2013	14.1
2014	13.3
2015	12.4
2016	11.7
2017	10.9
2018	11
2019	11.9
2020	14.2
2021	16.1