Year	kg per 2015 US$ of GDP
1990	0.49343042523814334
1991	0.4907198405669941
1992	0.48275731040218417
1993	0.4797147624443336
1994	0.4683244753952722
1995	0.4611764593439093
1996	0.45872524723604324
1997	0.46107399664144216
1998	0.44553023646134593
1999	0.42702013566335656
2000	0.4225002144579033
2001	0.4158553196874309
2002	0.3995173479173772
2003	0.3944273321102081
2004	0.38439392414061924
2005	0.37318149301087367
2006	0.3568325686648926
2007	0.35626619456621766
2008	0.34440029279845086
2009	0.32865614108136976
2010	0.33410595681706984
2011	0.31713690275158285
2012	0.29822124583242443
2013	0.2997125624420169
2014	0.29335490828970906
2015	0.27945412123698926
2016	0.26977417210361954
2017	0.26010524784090727
2018	0.26050454155901687
2019	0.24650545649011257
2020	0.22701802414715921