Year	kg per 2015 US$ of GDP
1990	0.7619024749717744
1991	0.767368702303611
1992	0.7471234299250951
1993	0.7401057224688173
1994	0.6752492251516788
1995	0.6880282477798265
1996	0.6918198064735445
1997	0.7029775489687518
1998	0.6967719128493852
1999	0.6898731889765152
2000	0.6378694150331301
2001	0.6810767351099515
2002	0.6795453904571651
2003	0.6767247148182866
2004	0.7062455182333934
2005	0.7588814252886921
2006	0.7476112083403266
2007	0.7498542371093334
2008	0.7247287942843789
2009	0.7205311944201068
2010	0.6944561488899891
2011	0.7009947909374772
2012	0.7165004924677546
2013	0.6974439913475138
2014	0.6943664973660031
2015	0.6870266017431156
2016	0.6850086335664148
2017	0.6829726982157552
2018	0.631018115058354
2019	0.5473975067697381
2020	0.5112703067266761