Year	% of population
1987	45.1
1990	38.6
1992	32.8
1994	27.7
1996	23.2
1998	21.6
2000	36
2003	35.4
2006	29.1
2009	25.3
2011	22.2
2013	14.4
2015	11.7
2017	8.6
2020	10.8