Year	kg per PPP $ of GDP
1990	1.1655170385918376
1991	1.1640045446899816
1992	1.1200073031540763
1993	1.0465730955275225
1994	0.9517645350246883
1995	0.870555290272667
1996	0.8482159181636786
1997	0.8250393643653248
1998	0.7767757063266013
1999	0.7096406599894451
2000	0.7489726792256512
2001	0.6904759323379703
2002	0.6458732617230066
2003	0.619397630989583
2004	0.5799227048178314
2005	0.5402587522784416
2006	0.5003188353873156
2007	0.4596040200057364
2008	0.4086632999777138
2009	0.39059683391670375
2010	0.3909894397794068
2011	0.36537374222347657
2012	0.34901991439771757
2013	0.3175950035353532
2014	0.2921971623704544
2015	0.28298294575059596
2016	0.27003803859597814
2017	0.2517454033203
2018	0.23489861574192655
2019	0.20410518529423685
2020	0.18906054161279504