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	9
1985	7
1986	8
1987	14
1988	20
1989	19
1990	36
1991	21
1992	8
1993	10
1994	17
1995	35
1996	11
1997	13
1998	12
1999	14
2000	15
2001	21
2002	40
2003	40
2004	40
2005	40
2006	40
2007	40
2008	40
2009	70
2010	70
2011	85
2012	100
2013	200
2014	329
2015	300
2016	300
2017	350
2018	350
2019	351.65
2020	649
2021	472
2022	500