Year	% of population
1987	35.4
1990	33.3
1992	30.9
1994	31.2
1996	29.5
1998	29.3
2000	29.1
2003	28.7
2006	24.6
2009	23
2011	22
2013	20.3
2015	19.3
2017	18.9
2020	20.6
2022	18.1