Year	metric tons
1992	29649100
1993	21530700
1994	16399233.41
1995	9476320
1996	11210020
1997	12358980
1998	6380160
1999	14248300
2000	11539396
2001	15865279
2002	15926090
2003	14738300
2004	12337671
2005	13750260
2006	16472690
2007	20082040
2008	15530034
2009	20763550
2010	12115916
2011	26825597.9
2012	12788631.4
2013	18157040.27
2014	17110959.3
2015	18585931.63
2016	20410625
2017	20129018
2018	20196033.6
2019	17509767.93
2020	20152658.33
2021	16556388.1
2022	22040639.83