Year	2017 PPP (% of population)
1989	58.1
1991	65.9
1995	58.2
1996	59.7
1998	57.9
1999	55.3
2000	51
2001	52.4
2002	52.4
2003	53.6
2004	51.8
2005	51.8
2006	50.5
2007	47.2
2008	50.9
2009	50.5
2010	49.1
2011	50
2012	47.1
2013	42.7
2014	42.7
2015	40.2
2016	38.7
2017	36.3
2018	33
2019	28.8
2021	28.4
2022	27.5