Year	kg per 2015 US$ of GDP
1990	1.1207123193803485
1991	1.1222496551096508
1992	1.1032666949458219
1993	1.07296230696311
1994	1.0304165119064888
1995	1.0366213688507129
1996	0.9951945565898754
1997	0.9583520844047428
1998	0.9420497576186823
1999	0.9091603229935059
2000	0.89317013027988
2001	0.8883330985226656
2002	0.8791486317715632
2003	0.897299058876895
2004	0.9007732984313433
2005	0.9002637497449597
2006	0.8886024128119253
2007	0.8665410061084073
2008	0.8431182750657888
2009	0.8385307046553897
2010	0.8367107260136936
2011	0.8404212199702803
2012	0.8213150971949804
2013	0.8024727898679505
2014	0.7756693328726805
2015	0.7367767937059435
2016	0.7099768837727055
2017	0.6931437233363468
2018	0.6865687847481634
2019	0.668387930870912
2020	0.6611316100611145