Year	2017 PPP (% of population)
1998	90.1
1999	88
2000	84.4
2001	73.7
2002	67.7
2003	64.8
2004	54.3
2005	36
2006	27.9
2007	20.7
2008	16.4
2009	15.6
2010	11.8
2011	10
2012	5.9
2013	3.4
2014	3.2
2015	4.1
2016	4.6
2017	3.3
2018	1.9
2019	2.4
2020	1.3