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	0
1995	0
1996	0
1997	0
1998	0
1999	0
2000	0
2001	0.4
2002	0
2003	0
2004	0
2005	0
2006	0.8
2007	0
2008	0
2009	0
2010	0
2011	0
2012	1
2013	0.1
2014	0.3
2015	0.3
2016	0.3
2017	0.3
2018	0.5
2019	0.3
2020	0.5
2021	0.5
2022	0.5