Year	kg per 2015 US$ of GDP
1990	0.47787723249783215
1991	0.48087700926202986
1992	0.49170411179373086
1993	0.4741219178630715
1994	0.4695526157401729
1995	0.46909816022836426
1996	0.4753657058519103
1997	0.4707781803973806
1998	0.4607178613578141
1999	0.4467652508310249
2000	0.44206950122828625
2001	0.42752006624453026
2002	0.4296033817209525
2003	0.43822768280533786
2004	0.4187404003061617
2005	0.4152566629669923
2006	0.3983150559403788
2007	0.41277594909550347
2008	0.39363664583463126
2009	0.3839856629289034
2010	0.3836832363945907
2011	0.3805170252456605
2012	0.3718563256697744
2013	0.3696910842709424
2014	0.36325639431857726
2015	0.3589746451664506
2016	0.3540938024117304
2017	0.3506422545534687
2018	0.3481273732145291
2019	0.3336084533521158
2020	0.3208151610061033