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	35
1983	9
1984	7
1985	8
1986	6
1987	3
1988	2
1989	3
1990	0
1991	0
1992	0
1993	0
1994	0
1995	0
1996	0
1997	0
1998	20
1999	20
2000	22
2001	14
2002	30
2003	30
2004	37
2005	45
2006	50
2007	60
2008	60
2009	70
2010	80
2011	90
2012	100
2013	130
2014	165
2015	230
2016	345
2017	515
2018	685
2019	855
2020	1030
2021	1150
2022	1375