Year	kg per 2015 US$ of GDP
1990	0.6095662381170889
1991	0.6208690219654643
1992	0.6352011000558573
1993	0.643720080313731
1994	0.6382217919020794
1995	0.6547004111631791
1996	0.6655324334951617
1997	0.6608792095542014
1998	0.6506285053819162
1999	0.6212312299861895
2000	0.6170745315681483
2001	0.6447970361284744
2002	0.6088026319840072
2003	0.6190754962607365
2004	0.6135534443579563
2005	0.5819563564047425
2006	0.5480309945819667
2007	0.530178488679397
2008	0.5368112387871351
2009	0.5024173365743925
2010	0.5073797678030726
2011	0.48502349012742013
2012	0.48759371785283256
2013	0.4885080819056692
2014	0.48615321257016986
2015	0.4619216060791925
2016	0.4627686878526097
2017	0.4572545195239259
2018	0.4550490843398357
2019	0.4566353288723401
2020	0.4250229035247313