Year	% of population
1999	34.1
2001	33.8
2002	31.4
2003	29.7
2004	27.2
2005	23.4
2006	22.6
2007	22.4
2008	20.4
2009	20.4
2010	21.6
2011	21.7
2012	21.4
2013	21.6
2014	22.6
2015	21.6
2016	25.2
2017	19
2018	19.7
2019	20.6
2020	16.1
2021	18.3
2022	20.1