Year	2017 PPP (% of population)
1997	7.4
1998	10.1
1999	16.6
2000	12.9
2001	8.8
2002	6.5
2003	6.5
2004	5.5
2005	4.4
2006	3.2
2007	2
2008	0.9
2009	0.8
2010	0.7
2011	0.5
2012	0.5
2013	0.4
2014	0.3
2015	0.4
2016	0.4
2017	0.4
2018	0.3
2019	0.3
2020	0.3