Year	2017 PPP (%)
1977	68.7
1983	65.9
1987	63.4
1993	62.1
2004	58.3
2009	54.9
2011	48.9
2015	47.3
2016	46.8
2017	43.1
2018	39.4
2019	37.9
2020	40.4
2021	38.2