Year	metric tons
1960	3750086
1961	3991421
1962	4131311
1963	3990906
1964	3857151
1965	4025271
1966	3915175
1967	3735380
1968	4037948
1969	3960762
1970	4359068
1971	4368469
1972	4120880
1973	4147777
1974	4098862
1975	4097641
1976	4406609
1977	4483794
1978	5044633
1979	5172817
1980	5248591
1981	5379649.08
1982	5644850.04
1983	5796785.109999999
1984	6360477.24
1985	6526224.52
1986	6797538
1987	7709474
1988	7756354.96
1989	7542990.33
1990	7662880.44
1991	7156118.16
1992	7064654.38
1993	7239771.74
1994	7156483.56
1995	6568206
1996	6461023
1997	6677143
1998	6413417
1999	6602178
2000	6405713
2001	6716888
2002	6775276
2003	6854483
2004	6958612
2005	6776223
2006	6701970
2007	6523885
2008	5998803
2009	5859796
2010	6031748
2011	6641777.33
2012	6515471.23
2013	6541423.03
2014	6380982.5
2015	6474240.7
2016	6376961.47
2017	6511323.16
2018	6313483.039999999
2019	6361214.51
2020	5652657.58
2021	5713894.29
2022	5612299.7700000005