Year	kg per 2015 US$ of GDP
1990	0.3911729705332102
1991	0.3816612551415134
1992	0.3658521856055688
1993	0.361369121909588
1994	0.35095132417468455
1995	0.34702520338834836
1996	0.35062903715842075
1997	0.3348197973592809
1998	0.32419096475685777
1999	0.3095546259598624
2000	0.29872830775332204
2001	0.29732010590337943
2002	0.293350086788912
2003	0.29836147711896444
2004	0.29118390139830747
2005	0.2842942489913707
2006	0.2753683630580272
2007	0.26376411012538775
2008	0.2561331446481457
2009	0.24818533878584179
2010	0.24934314576570266
2011	0.23750768054895927
2012	0.2345670024575673
2013	0.22887297928610986
2014	0.21437095325772323
2015	0.21376271668521205
2016	0.21035795791577389
2017	0.20627988854649926
2018	0.19767661143459517
2019	0.18481695337911602
2020	0.1768921852899252