Year	2011 PPP (% of population)
1979	8.1
1989	23.9
1991	21.9
1995	16.3
1997	15
1998	15.2
1999	13.4
2000	12.4
2001	15.5
2002	11.2
2003	11.2
2004	10.1
2005	10
2006	10.5
2007	7.8
2008	5.2
2009	3.2
2010	4.5
2011	3
2012	4.1
2013	2.8
2014	3.5
2015	2
2016	2.2
2017	2.5