Year	kg per PPP $ of GDP
1990	0.6183407990932991
1991	0.55548887674423
1992	0.5101621129105908
1993	0.5000184808423145
1994	0.4721126302126753
1995	0.4547410824327962
1996	0.4586587792183743
1997	0.4329802149672386
1998	0.41609209499285155
1999	0.386189102294317
2000	0.3712664193738532
2001	0.3627461353036538
2002	0.34624685086592183
2003	0.3389778818764497
2004	0.31755325954988245
2005	0.30601477452233306
2006	0.28941597568970434
2007	0.26249992228161073
2008	0.25441403416090386
2009	0.2436993393444902
2010	0.24273115658165653
2011	0.2185864651705178
2012	0.21797446966433665
2013	0.21390079364405
2014	0.19332541805026934
2015	0.19087138423913977
2016	0.17937977628052146
2017	0.16691353979866255
2018	0.1546682250663651
2019	0.1360849156064431
2020	0.12529485417997316