Year	% of population
2000	6.7
2001	7.1
2002	7.7
2003	8.3
2004	9
2005	6
2006	10.2
2007	15.2
2008	11.6
2009	12.3
2010	13
2011	13.7
2012	15.4
2013	15.2
2014	13.5
2015	16.6
2016	17.3
2017	18
2018	18.7
2019	19.1
2020	20.1
2021	20.8
2022	21.5