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	0
1985	0
1986	0
1987	0
1988	0
1989	53
1990	60
1991	0
1992	0
1993	0
1994	0
1995	0
1996	4
1997	4
1998	4
1999	4
2000	5
2001	5
2002	5
2003	5
2004	5
2005	5
2006	75
2007	25
2008	25
2009	25
2010	25
2011	33
2012	33
2013	33
2014	35
2015	35
2016	35
2017	35
2018	33
2019	33
2020	33
2021	35
2022	42