Year	2017 PPP (% of population)
1981	4.2
1989	3.3
1992	2.6
1995	2.4
1996	2.7
1997	2.5
1998	2.4
2000	2.4
2001	2.8
2002	3.9
2003	5.1
2004	6.5
2005	5.8
2006	4.5
2007	3.6
2008	2.2
2009	2.2
2010	1.6
2011	1.3
2012	1.3
2013	1.1
2014	0.8
2015	0.8
2016	0.7
2017	0.5
2018	0.4
2019	0.5
2020	0.9
2021	0.8
2022	0.8