Year	2011 PPP (%)
1981	33.2
1988	30.6
1990	27.9
1992	23.5
1994	17.9
1996	14.8
1998	14.3
1999	16.7
2000	17
2002	12.6
2004	9.9
2006	7.5
2007	6.3
2008	5.5
2009	4.7
2010	4.1
2011	2.7
2012	2.9
2013	2.3
2014	2
2015	1.2
2016	1.5
2017	1.4