Year	kg per 2015 US$ of GDP
1990	0.7612304649879075
1991	0.7507340234731189
1992	0.760384439202023
1993	0.7866406137962008
1994	0.7955710933271907
1995	0.7997263346488914
1996	0.7872963493051504
1997	0.7934250038512499
1998	0.8001141973337653
1999	0.7487185123151162
2000	0.7352102255929617
2001	0.7838802766597238
2002	0.7767143705927327
2003	0.7954648376594663
2004	0.8082700808544573
2005	0.7631542718909209
2006	0.7269135210928079
2007	0.7121599092797092
2008	0.7291747721438068
2009	0.6983717798525044
2010	0.7003565471416987
2011	0.6637793868234989
2012	0.6789432098454572
2013	0.6771944347673199
2014	0.6777524751663806
2015	0.6407970229630638
2016	0.6314057094263119
2017	0.6264256331655383
2018	0.6181342886515343
2019	0.6170178882631561
2020	0.5663147190741866