Year	kg per 2015 US$ of GDP
1990	0.5929010077126103
1991	0.5747606944009286
1992	0.4660223431217613
1993	0.40609887706225833
1994	0.7063064121376924
1995	0.6543868996269192
1996	0.5044077737752262
1997	0.4974034095931468
1998	0.4940965675243963
1999	0.5150284773928855
2000	0.4388760036389864
2001	0.4403481050886476
2002	0.4100430914854314
2003	0.36597069481459077
2004	0.34930894680538194
2005	0.3285040445094453
2006	0.3125821828075999
2007	0.3094860726014321
2008	0.3012715781260381
2009	0.30745485385270926
2010	0.2413389270808765
2011	0.22650101874682924
2012	0.21263550065067535
2013	0.24299517952820693
2014	0.24590474634104525
2015	0.2500218008419758
2016	0.2717694293446507
2017	0.2639366330549657
2018	0.25780072950504024
2019	0.26550362726776455
2020	0.26468262454413866