Year	2011 PPP (% of population)
1987	11.7
1990	8.1
1992	4.7
1994	5
1996	3.4
1998	3.5
2000	4.4
2003	4.2
2006	2.4
2009	2.6
2011	1.6
2013	0.9
2015	1.3
2017	0.7