Year	2017 PPP (% of population)
1981	6.7
1987	7
1989	5.3
1992	4.5
1995	9.9
1998	10.4
1999	11.8
2001	10.3
2002	16.4
2003	19.7
2004	16.6
2005	14.4
2006	7.1