Year	kg per 2015 US$ of GDP
1990	0.6092340354003402
1991	0.6205447304195603
1992	0.6348191925194088
1993	0.643295223540844
1994	0.6378534130184111
1995	0.6543186372279853
1996	0.6651408723757083
1997	0.6604753920231563
1998	0.6502492193113114
1999	0.6208986171037439
2000	0.616709987502644
2001	0.6444685600454078
2002	0.6085558010399712
2003	0.6188549454116878
2004	0.6134088920200927
2005	0.5818015774109901
2006	0.5478763899128049
2007	0.5300204924795483
2008	0.5366792743537667
2009	0.5023527632195817
2010	0.5072939092885588
2011	0.4848979028444991
2012	0.48746803417192436
2013	0.4883753648207534
2014	0.4860405424739652
2015	0.4618246074296275
2016	0.46266356398426617
2017	0.4571305089894111
2018	0.4549265889065758
2019	0.4564857577953678
2020	0.4249588134542025