Year	2017 PPP (% of population)
1984	74.2
1987	74.3
1990	62.8
1993	62.1
1996	51.3
1998	69.1
1999	46
2000	43.6
2001	39.9
2002	26.8
2003	26.4
2004	27
2005	24.6
2006	30.6
2007	25.2
2008	24.7
2009	21
2010	18.3
2011	15.7
2012	13.7
2013	11.2
2014	9.3
2015	8.3
2016	7.5
2017	6.6
2018	5.4
2019	4.4
2020	3.8
2021	3.5
2022	2.5
2023	1.9