Year	metric tons
1960	800
1961	1000
1962	1000
1963	1000
1964	1000
1965	1200
1966	1200
1967	1200
1968	1200
1969	1200
1970	1300
1971	1300
1972	1300
1973	1700
1974	1625
1975	1449
1976	1368
1977	2004
1978	2688
1979	2704
1980	2906
1981	2800
1982	2241
1983	3477
1984	3669
1985	3024
1986	2318
1987	2365
1988	2743
1989	2910
1990	3005
1991	2805
1992	2835
1993	2854
1994	2783
1995	2949
1996	4346
1997	4238
1998	4117
1999	3601
2000	3589
2001	3927
2002	3449
2003	3526
2004	3201
2005	3505
2006	3468
2007	3566
2008	3228
2009	2649
2010	3373
2011	2976
2012	2955
2013	2848
2014	2983
2015	2574
2016	2985
2017	2731
2018	3203
2019	3050
2020	2073.35
2021	2187.51
2022	2290