Year	2017 PPP (%)
1984	40.8
1985	38.8
1986	36.8
1987	35.5
1988	33.1
1989	36.7
1990	36
1991	35.2
1992	34
1993	32.7
1994	30.3
1995	28.3
1996	26.7
1997	26.7
1998	27.1
1999	25.8
2000	24.1
2001	22.7
2002	20.3
2003	18.4
2004	16.4
2005	14.3
2006	13.5
2007	12.3
2008	11.6
2009	10.6
2010	9.3
2011	7.6
2012	6.7
2013	4.4
2014	3.8
2015	3.2
2016	2.9
2017	2.6
2018	2.2
2019	1.9
2020	1.8
2021	1.8
2022	1.5