Year	metric tons
1960	3518587
1961	3646538
1962	3631936
1963	3819608.1
1964	4048204.1
1965	4225091.4
1966	4277556.8
1967	4505673
1968	4649384
1969	4443630
1970	4474947
1971	4349672
1972	4295475
1973	4482674
1974	4473543
1975	4305408
1976	4172042
1977	3854528
1978	3842488.1
1979	3630522.6999999997
1980	3774260.9
1981	3962553.65
1982	4049768.1
1983	4007215.62
1984	4105346.57
1985	4106895.33
1986	4143919.0000000005
1987	4133269.16
1988	4167618.76
1989	4084211.9
1990	3831734.17
1991	3688759.8499999996
1992	4243634.279999999
1993	4295879.27
1994	4184433.6099999994
1995	4380103.050000001
1996	4223645.6
1997	4165842.8900000006
1998	4217530.98
1999	4103501.6900000004
2000	3974354.3900000006
2001	4125666.22
2002	3869529.04
2003	3859826.3399999994
2004	3822954.32
2005	3845662.5900000003
2006	3874805.96
2007	3715254.8899999997
2008	3585702.95
2009	3507336.21
2010	3625623.14
2011	3481404.21
2012	3214458.5
2013	3354596.6100000003
2014	3591888.21
2015	3406950.76
2016	3428104.8
2017	3519168.55
2018	3425251.4700000007
2019	3161303.65
2020	2853266.29
2021	2876194.4400000004
2022	2848956.0999999996