Year	2017 PPP (% of population)
1997	13
1998	24
1999	33.5
2000	31.1
2001	23.3
2002	13.6
2003	5.6
2004	6.6
2005	10.9
2006	2
2007	1
2008	1
2009	0.7
2010	0.4
2011	0.2
2012	0.1
2013	0
2014	0
2015	0
2016	0.1
2017	0
2018	0
2019	0
2021	0