Year	kg per 2015 US$ of GDP
1990	0.869177729561298
1991	0.8621857081050293
1992	0.8720869173408928
1993	0.7680240989118537
1994	0.6840383026378402
1995	0.5898968488816652
1996	0.5453895192078616
1997	0.5729806989945025
1998	0.5183621267997216
1999	0.48993861911344455
2000	0.4677360190206871
2001	0.4432433414952814
2002	0.4616440737422075
2003	0.4785179562967269
2004	0.48540740575835045
2005	0.4896565853741384
2006	0.5065730013202558
2007	0.5383822375933585
2008	0.542410323453061
2009	0.5592539186757759
2010	0.5818841318618472
2011	0.6016115804362621
2012	0.6069854127879014
2013	0.6073281677790208
2014	0.6189174179006037
2015	0.6061448434073544
2016	0.6198887920886206
2017	0.6032843181770222
2018	0.5856074950304432
2019	0.5715358442880154
2020	0.5271782896080021