Year	2011 PPP (%)
1998	42.3
2000	55.3
2001	52.8
2002	51.7
2003	49.4
2004	34.8
2005	38.5
2006	29.9
2007	29.4
2008	22.6
2009	20.7
2010	22.7
2011	21.4
2012	22.6
2013	24.3
2014	21
2015	23.2
2016	20.9
2017	20.9