Year	% of population
2000	13.8
2001	14.3
2002	14.6
2003	15
2004	15.3
2005	15.8
2006	16
2007	16.1
2008	16.1
2009	16.1
2010	16
2011	15.8
2012	15.5
2013	15
2014	14.6
2015	13.9
2016	13.4
2017	12.6
2018	11.9
2019	11.1
2020	10.4
2021	9.6
2022	9