Year	2017 PPP (% of population)
1981	23.9
1982	24.4
1983	30.6
1984	29.9
1985	25.8
1986	12.3
1987	19.9
1988	22.4
1989	20.4
1990	24
1992	23.3
1993	22.1
1995	14.7
1996	16
1997	16
1998	14.3
1999	15
2001	13
2002	11.7
2003	12.6
2004	11.1
2005	10
2006	8.3
2007	7.9
2008	6.5
2009	6.1
2011	5.3
2012	4.5
2013	3.7
2014	3.3
2015	3.9
2016	4.7
2017	5.3
2018	5.3
2019	5.4
2020	2
2021	5.8
2022	3.5