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	0
1978	0
1979	0
1980	0
1981	0
1982	0
1983	0
1984	8
1985	12
1986	18
1987	19
1988	20
1989	40
1990	45
1991	45
1992	40
1993	42
1994	60
1995	88
1996	93
1997	66
1998	81
1999	61
2000	69
2001	72
2002	0
2003	0
2004	0
2005	0
2006	0
2007	0
2008	0
2009	73
2010	209
2011	100
2012	100
2013	100
2014	100
2015	100
2016	100
2017	100
2018	100
2019	100
2020	100
2021	100
2022	100