Year	kg per 2015 US$ of GDP
1990	0.34191669407949127
1991	0.34177329327190625
1992	0.33899518336837975
1993	0.33361378237832745
1994	0.3316132215474584
1995	0.33682823502533094
1996	0.34569024802166826
1997	0.34871875206461195
1998	0.35246766595210655
1999	0.34813726081314
2000	0.34724083815325496
2001	0.34698665253327865
2002	0.3467318060790127
2003	0.3439706026297516
2004	0.34079631684469075
2005	0.33883699535454953
2006	0.33211952721351107
2007	0.326141496324797
2008	0.32406020098767807
2009	0.3228482282032408
2010	0.3245285005536738
2011	0.32361591538312157
2012	0.32954207035160016
2013	0.32904436679138227
2014	0.3263322160299439
2015	0.3231082498966281
2016	0.3167001059627402
2017	0.30641335760837896
2018	0.2922998025732935
2019	0.2879265375038176
2020	0.27368161130986723