Year	metric tons
1960	0
1961	0
1962	0
1963	0
1964	0
1965	0
1966	0
1967	0
1968	0
1969	0
1970	0
1971	0
1972	0
1973	0
1974	0
1975	0
1976	0
1977	2
1978	38
1979	25
1980	20
1981	32
1982	135
1983	148
1984	355
1985	850
1986	1462
1987	2201
1988	2772
1989	3092
1990	3404
1991	3140
1992	3240
1993	3340
1994	3440
1995	3550
1996	3500
1997	3450
1998	3410
1999	4150
2000	4512
2001	4512
2002	6155
2003	2974
2004	4500
2005	5675
2006	8024
2007	5621
2008	5955
2009	5189
2010	3957
2011	1157
2012	656.05
2013	842.9
2014	881
2015	607
2016	952
2017	1347
2018	1620.63
2019	1161.45
2020	926.75
2021	884.2
2022	945