Year	kg per 2015 US$ of GDP
1990	1.3529009172601678
1991	1.389049699143095
1992	1.3223041291629083
1993	1.2792544300550115
1994	1.225044647210726
1995	1.241877273455838
1996	1.165440080614063
1997	1.1241272012697083
1998	1.0080484362175788
1999	0.9496731306294045
2000	0.9295883799802812
2001	0.9215555558204079
2002	0.8720814974151295
2003	0.8946851048350029
2004	0.7940082072672812
2005	0.7621387674136002
2006	0.7220929794949207
2007	0.6766409542897481
2008	0.6631720499771308
2009	0.6107552168227205
2010	0.6164244714948357
2011	0.618802408945918
2012	0.6125282084290029
2013	0.6019182159371891
2014	0.5740401951212469
2015	0.5157620506735991
2016	0.5118885042022788
2017	0.4942044952511108
2018	0.49789085809184974
2019	0.4788567457181268
2020	0.45440419584042097