Year	kg per PPP $ of GDP
1990	1.2139326060082796
1991	1.2021731456937945
1992	1.2116661148185157
1993	1.1147251265370584
1994	0.9669469107971309
1995	0.9091442572109508
1996	0.8346002092919964
1997	0.778709736392675
1998	0.7230395344712935
1999	0.7032926355813237
2000	0.6209491612206246
2001	0.5788672516249423
2002	0.5317990135737152
2003	0.5030032858739033
2004	0.4575717464816885
2005	0.4308522471745642
2006	0.3726750043438397
2007	0.3259784080300235
2008	0.29066909139386493
2009	0.2727598296567346
2010	0.25875238688979135
2011	0.24067470039010197
2012	0.22159721894003628
2013	0.2170411106695919
2014	0.19350548236277396
2015	0.1886642372228317
2016	0.19503433890894278
2017	0.20479553341621054
2018	0.19316578477881402
2019	0.16762362348177323
2020	0.15196540382205947