Year	2017 PPP (% of population)
1990	21.8
1995	43.6
1997	38
1999	41.4
2001	39.5
2002	51.7
2003	44.7
2004	42.8
2005	39.1
2006	43.8
2007	40.3
2008	37.2
2009	35.7
2010	34.1
2011	32.2
2012	27
2013	23.3
2014	22.6
2015	22.6
2016	23.7
2017	21
2018	19.6
2019	19.7
2020	22.3
2021	20.8
2022	19.9