Year	kg per PPP $ of GDP
1990	0.649114576365043
1991	0.6196828707360486
1992	0.59258043187368
1993	0.5731420585109961
1994	0.5489754910218982
1995	0.5301408449909725
1996	0.517811418710401
1997	0.5028239478431583
1998	0.48321790057157404
1999	0.46364892898170673
2000	0.44387903029522785
2001	0.4276700568446025
2002	0.40794048558183804
2003	0.39983465719736666
2004	0.3799146913137409
2005	0.3605174621513556
2006	0.3337778061091293
2007	0.3195353565559381
2008	0.30119381834425524
2009	0.2884649812444828
2010	0.2884698301861409
2011	0.2713974317999451
2012	0.25855349506190706
2013	0.24970650388080393
2014	0.23669313693826696
2015	0.2268196226517037
2016	0.21625770862645233
2017	0.20527455047493068
2018	0.19754246392070832
2019	0.1815703356830096
2020	0.16758274015756622