Year	$ 2017 PPP (%)
1999	48.13
2001	77.54
2002	70.84
2004	70.27
2005	61.77
2006	62.37
2007	63.08
2009	50.61
2010	45.59
2011	36.07
2012	34.49
2013	35.73
2014	36.14
2015	31.24
2016	33.13
2017	30.97
2018	22.36