Year	kg per PPP $ of GDP
1990	1.8745362476630907
1991	1.768834064386794
1992	1.7446872523024455
1993	1.6019165580958032
1994	1.5067257035249908
1995	1.465218242093599
1996	1.4227044435956941
1997	1.267639475851123
1998	1.1207801093472536
1999	1.0268734830450357
2000	0.9147085781268051
2001	0.8340869756745513
2002	0.7823702579639159
2003	0.7274468965038005
2004	0.6746768105473402
2005	0.6055853588390248
2006	0.5560958048615412
2007	0.48611036819419284
2008	0.4547073248090475
2009	0.4281464565072906
2010	0.4216850290373954
2011	0.3721772854019778
2012	0.3490873554550636
2013	0.3335558958945349
2014	0.3303985167112714
2015	0.31983163200848314
2016	0.326901489338714
2017	0.322933633948985
2018	0.3135708478492719
2019	0.2745737234423422
2020	0.23489576451343888