Year	kg per 2015 US$ of GDP
1990	0.3460193182096165
1991	0.34835028806566093
1992	0.3471570840641602
1993	0.34148327744680473
1994	0.3389232263769578
1995	0.3443957008246899
1996	0.3533666608066528
1997	0.3561397597382108
1998	0.36044790293482926
1999	0.356478517747815
2000	0.35586390165298537
2001	0.35672144794584915
2002	0.3569145505839998
2003	0.3541385523787717
2004	0.351588048081689
2005	0.3492708015435886
2006	0.3421062226566711
2007	0.3354218989880784
2008	0.3330873109803492
2009	0.3317733601258694
2010	0.3328395564831183
2011	0.33168026314376003
2012	0.3375354418176913
2013	0.3367776546874469
2014	0.33433975671706007
2015	0.3307144477990492
2016	0.32443515985181964
2017	0.3136765673158427
2018	0.2985408355596065
2019	0.2945010065929341
2020	0.27912029150588175