Year	% of population
2000	0.6
2001	0.5
2002	0.5
2003	0.5
2004	0.5
2005	0.5
2006	0.5
2007	0.5
2008	0.5
2009	0.5
2010	0.5
2011	0.5
2012	0.5
2013	0.6
2014	0.6
2015	0.6
2016	0.6
2017	0.7
2018	0.7
2019	0.8
2020	0.9
2021	1
2022	1