Year	2017 PPP (% of population)
1977	63.5
1983	56.6
1987	50.9
1993	48
2004	40.6
2009	33.5
2011	22.9
2015	18.8
2016	18.1
2017	13.4
2018	11.1
2019	13.2
2020	15.5
2021	12.9