Year	$ 2017 PPP (%)
1997	3.88
2002	1.21
2003	1.78
2004	0.99
2005	1.2
2006	0.33
2007	0.19
2008	0.24
2009	0.63
2010	0.1
2011	0.33
2012	0.05
2013	0.03
2014	0
2015	0.02
2016	0