Year	2017 PPP (% of population)
1977	0.2
1978	0.5
1979	0.5
1980	0.2
1981	0
1982	0
1983	0.2
1984	0
1986	0.2
1987	1
1989	0
1991	0.2
1993	1.2
1995	0.7
1998	1.7
2000	1.2
2002	1.5
2003	0.8
2004	0.6
2005	0.6
2006	0.7
2007	0.7
2008	0.7
2009	0.9
2010	1.3
2011	1.2
2012	1.2
2013	1.4
2014	1.2
2015	1.9
2016	1.6
2017	1.4
2018	1.5
2019	1
2020	0.8
2021	0.8