Year	kg per 2015 US$ of GDP
1990	0.40970245145776985
1991	0.41577419820068806
1992	0.4160384766464632
1993	0.42045747488173546
1994	0.40334601826027877
1995	0.4002572211310769
1996	0.3870341092238174
1997	0.4094603492120464
1998	0.4086124297269018
1999	0.3665705645759372
2000	0.37572726541290363
2001	0.3732400683538755
2002	0.3505856161125846
2003	0.3335033587489502
2004	0.3160201607624227
2005	0.30986718511444855
2006	0.29039376914053744
2007	0.27915347443785904
2008	0.27294151707976033
2009	0.2804841893451859
2010	0.27473924275608236
2011	0.2794176149185016
2012	0.27063905365795576
2013	0.28492440798011875
2014	0.28095589304826096
2015	0.27604533619281996
2016	0.2787750096156804
2017	0.2491804369013834
2018	0.25476884589034143
2019	0.24637622480802748
2020	0.265018557668443