Year	kg per 2015 US$ of GDP
1990	0.43643250940938455
1991	0.4009024637557993
1992	0.46290856478646353
1993	0.5202207898021844
1994	0.47013714726051264
1995	0.45779102913569686
1996	0.4261406148427052
1997	0.4491401267423552
1998	0.47678750264533537
1999	0.48054263491279076
2000	0.45466332909072144
2001	0.46930202239637114
2002	0.46845602812315423
2003	0.47273929832335815
2004	0.44295252547096686
2005	0.4317531847264832
2006	0.4138301073377783
2007	0.41706828664721807
2008	0.38833408754543736
2009	0.3911693115581627
2010	0.3794700215708694
2011	0.3713059826785267
2012	0.3475919689084639
2013	0.34080022728679976
2014	0.32640472366107237
2015	0.32546401040394246
2016	0.31919705376361657
2017	0.3185242274051859
2018	0.2919822060711876
2019	0.283808710957406
2020	0.2934118773669836