Year	2017 PPP (% of population)
1977	4
1978	4.2
1979	3.5
1980	2.5
1981	1.9
1982	1.2
1983	1.7
1984	2
1986	2.5
1987	2.7
1989	0.7
1991	1.7
1993	4.2
1995	3.5
1998	4
2000	3.5
2002	2.7
2003	2.1
2004	1.7
2005	1.9
2006	1.6
2007	1.7
2008	1.8
2009	2.1
2010	2.7
2011	2.7
2012	3.1
2013	3.2
2014	3.1
2015	3.9
2016	3.4
2017	3.3
2018	3.2
2019	2.6
2020	2.2
2021	1.7