Year	2017 PPP (% of population)
1981	17.3
1989	13.6
1992	11.1
1995	11
1996	11.6
1997	11.9
1998	11.8
2000	12.5
2001	14.1
2002	18.5
2003	24.5
2004	25.1
2005	22.7
2006	22.3
2007	19.6
2008	14.7
2009	13.6
2010	12
2011	8.5
2012	7.8
2013	7.4
2014	6.3
2015	6
2016	5.6
2017	4.6
2018	4.9
2019	5.1
2020	7.2
2021	6.7
2022	6.4