Year	2017 PPP (% of population)
1984	92.4
1987	93.3
1990	88.1
1993	87.5
1996	81.2
1998	90.7
1999	81.8
2000	81.6
2001	79.3
2002	67.7
2003	65.5
2004	65.8
2005	63.5
2006	68.1
2007	60.8
2008	59.7
2009	57.5
2010	50.7
2011	47.6
2012	46.1
2013	43.6
2014	40.5
2015	35.8
2016	33.5
2017	29.7
2018	26.4
2019	24.7
2020	23.5
2021	22.4
2022	20.2
2023	18.1