Year	2017 PPP (%)
1984	49.8
1985	48.2
1986	45
1987	44.9
1988	44.2
1989	45
1990	45
1991	44.9
1992	44.7
1993	44.5
1994	43.9
1995	43
1996	42.4
1997	42
1998	42
1999	41.9
2000	41
2001	40.3
2002	39.2
2003	38.2
2004	36.8
2005	35.5
2006	34.5
2007	33.3
2008	32.4
2009	31.5
2010	30
2011	28.5
2012	27.5
2013	26
2014	25.3
2015	24.6
2016	24.1
2017	23.2
2018	22
2019	21.3
2020	21.9
2021	21.5
2022	20.8