Year	% of population
2000	19
2001	19.7
2002	19.9
2003	20.1
2004	20.3
2005	20.9
2006	21.2
2007	21.6
2008	22.1
2009	22.6
2010	22.9
2011	23
2012	23.5
2013	23.4
2014	23.6
2015	23.7
2016	23.65
2017	23.3
2018	23.3
2019	23.1
2020	22.8
2021	22
2022	21.9