Year	2011 PPP (%)
1997	34.1
1998	43.6
1999	51.2
2000	50.8
2001	44.6
2002	34.4
2003	26.7
2004	27.3
2005	32.4
2006	12.8
2007	9.1
2008	9.5
2009	9
2010	7.3
2011	6
2012	5.5
2013	4
2014	3.5
2015	3
2016	3
2017	3