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	0
1990	0
1991	0
1992	0
1993	0
1994	5
1995	5
1996	5
1997	5
1998	5
1999	5
2000	5
2001	5
2002	5
2003	5
2004	5
2005	5
2006	5
2007	5
2008	8
2009	8
2010	8
2011	12
2012	18
2013	19
2014	21
2015	20
2016	20
2017	20
2018	20
2019	20
2020	20
2021	20
2022	20