Year	$ 2017 PPP (%)
1999	49.45
2001	78.7
2002	72.03
2004	71.31
2005	62.77
2006	63.37
2007	64.48
2009	52.17
2010	47.09
2011	37.25
2012	35.54
2013	36.77
2014	37.21
2015	32.11
2016	34.26
2017	32.15
2018	23.54