Year	metric tons
1960	3739271
1961	3879934
1962	3912547
1963	4106339.1
1964	4353357.1
1965	4542945.4
1966	4573952.8
1967	4799127
1968	4988743
1969	4798191
1970	4882357
1971	4741552
1972	4769804
1973	4955491
1974	4969241
1975	4850306
1976	4692406
1977	4445984
1978	4473232.1
1979	4232441.699999999
1980	4393861.9
1981	4624267.65
1982	4758353.1
1983	4736871.62
1984	4838445.57
1985	4917893.33
1986	4960921
1987	4962693.16
1988	5003704.76
1989	4898617.9
1990	4674972.17
1991	4530577.85
1992	5075601.279999999
1993	5110089.27
1994	5082580.609999999
1995	5346036.05
1996	5226220.6
1997	5177354.890000001
1998	5345518.9799999995
1999	5256166.69
2000	5099666.390000001
2001	5223094.22
2002	4861813.04
2003	4909257.34
2004	4822671.32
2005	4827866.59
2006	4890255.16
2007	4752514.29
2008	4535194.75
2009	4494606.61
2010	4569934.42
2011	4406698.2
2012	4102484.82
2013	4208476.12
2014	4497634.73
2015	4325588.95
2016	4398799.7700000005
2017	4522080.749999999
2018	4459823.01
2019	4141185.999999999
2020	3788300.58
2021	3856092.3200000003
2022	3815972.9500000007