Year	kg per 2015 US$ of GDP
1990	0.6948553069192566
1991	0.6895729352652359
1992	0.7034122728493283
1993	0.7337946136189492
1994	0.7660202040442258
1995	0.7658543177192417
1996	0.7550667400461927
1997	0.759750088353756
1998	0.7304665212799183
1999	0.742611089802196
2000	0.7273138529372906
2001	0.7518967981668819
2002	0.767584647897244
2003	0.7573023873486197
2004	0.7415174573154214
2005	0.7532939293712781
2006	0.7524064370333388
2007	0.7484598749140045
2008	0.7589540261636956
2009	0.7789456931098523
2010	0.7737062450930057
2011	0.7612770709609397
2012	0.7729225056661235
2013	0.7723162178370524
2014	0.7760311274458294
2015	0.7663967067576897
2016	0.741320340558031
2017	0.7372878860251721
2018	0.7178916604346791
2019	0.7104526183905686
2020	0.712925187877122