Year	% of population
2001	12.7
2002	12.6
2003	12
2004	12.2
2005	12
2006	12.2
2007	12.1
2008	12.8
2009	13.7
2010	15.6
2011	17.9
2012	19.9
2013	21.4
2014	22
2015	21.6
2016	20.9
2017	20.2
2018	19.8
2019	19.9
2020	19.5
2021	19