Year	2017 PPP (% of population)
1984	14.9
1987	14.8
1989	13.8
1992	13.8
1995	13.4
1997	8.8
2003	8.2
2006	4.9
2008	5.3
2011	1.8
2013	0.6
2015	0.4
2018	0.2
2021	0.1