Year	% of population
1990	72
1993	62.7
1996	51.3
1999	49.9
2002	45.1
2005	38.5
2008	36.3
2010	34.6
2011	32.3
2012	31.3
2013	27.3
2014	26.3
2015	25
2016	24.3
2017	24.4
2018	23.3
2019	22.2
2020	20.6