Year	2017 PPP (% of population)
1981	76.9
1988	76.2
1990	72.6
1992	66.1
1994	60.4
1996	56.1
1998	54.1
1999	58.3
2000	59
2002	50.8
2004	44.3
2006	36.9
2007	34.8
2008	32.7
2009	29.8
2010	27.4
2011	22.9
2012	22.5
2013	19.5
2014	18.7
2015	14.6
2016	15.7
2017	15.1
2018	15.6
2019	13.1
2020	13.2
2021	12.2