Year	% of population
2004	19.4
2005	23.5
2006	21.2
2007	25.9
2008	26.4
2009	20.9
2010	19
2011	19.2
2012	19.4
2013	21.2
2014	22.5
2015	21.8
2016	22.1
2017	23.3
2018	22.9
2019	21.6
2020	23.4
2021	22.5
2022	22.5