Year	metric tons
1960	4671108
1961	6546239
1962	8546582
1963	8631622
1964	11361368
1965	9372860
1966	11492500
1967	12649471
1968	13443841
1969	11790397
1970	15442626
1971	13895969
1972	7533042
1973	5359633
1974	7527352
1975	6720176
1976	8303322
1977	6845771
1978	9010989
1979	10145447
1980	9645773
1981	10441885.79
1982	11533764.04
1983	9375311.05
1984	12193696.27
1985	13947814.24
1986	16061914.480000002
1987	14052172.610000001
1988	16481947.479999999
1989	17925762.41
1990	16177184.89
1991	17142969.03
1992	17946351.89
1993	19289036.32
1994	24250147.689999998
1995	21605103.06
1996	21792312.41
1997	19263496.45
1998	12470694.02
1999	18326729.729999997
2000	20010298
2001	17161064
2002	18285122.58
2003	14862990.05
2004	19789403.43
2005	19022276.560000002
2006	16696347.3
2007	16537600.690000001
2008	16757186.66
2009	16029440.36
2010	12277604.729999999
2011	16665351.56
2012	12626036.51
2013	12980533.77
2014	11146052.73
2015	11765213.729999999
2016	10538674.31
2017	11566743.760000002
2018	14593813.870000001
2019	12179880.190000001
2020	12786593.950000001
2021	14353282.810000002
2022	12980116.479999999