Year	% of population
2000	16.7
2001	17.3
2002	17.7
2003	18.2
2004	18.6
2005	19.2
2006	19.7
2007	20.4
2008	20.6
2009	21.3
2010	21.8
2011	22.7
2012	23.3
2013	24
2014	24.9
2015	26
2016	27.3
2017	28.7
2018	29.9
2019	31.1
2020	32.6
2021	34.1
2022	35.5