Year	2017 PPP (% of population)
1979	39.7
1989	50.1
1991	48.1
1995	39.3
1997	39.1
1998	38.7
1999	36.5
2000	35
2001	40
2002	37.1
2003	35.8
2004	34.7
2005	34.5
2006	33.9
2007	30.5
2008	23.2
2009	23
2010	21.7
2011	18.3
2012	18.8
2013	18.2
2014	16.8
2015	15.4
2016	14.5
2017	14
2018	12.5
2019	12.1
2021	12.9
2023	12.9