Year	kg per 2015 US$ of GDP
1990	1.331293475408374
1991	1.3806466395752155
1992	1.3492412668212523
1993	1.307862363784698
1994	1.2297096502845268
1995	1.1710882166713756
1996	1.1561008151526249
1997	1.095306285043755
1998	1.0016678540214727
1999	0.928207655182502
2000	0.8837586054125777
2001	0.8717990289360926
2002	0.8240895976225349
2003	0.8236392509408238
2004	0.7770081977900141
2005	0.739840456721655
2006	0.7113665743180202
2007	0.6732061400842947
2008	0.6319278188270688
2009	0.6057420961204252
2010	0.6177781894576341
2011	0.5977158941044644
2012	0.5701154706295968
2013	0.544349423389353
2014	0.5109843067750283
2015	0.49841092485532285
2016	0.4940825277302399
2017	0.4896636256368934
2018	0.4627398650390431
2019	0.42246850985544515
2020	0.40675088344336735