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	1885
1993	1850
1994	1033
1995	821
1996	580
1997	580
1998	698
1999	1144
2000	1133
2001	866
2002	465
2003	569
2004	218
2005	250
2006	350
2007	1065
2008	601
2009	619
2010	617
2011	795
2012	861
2013	4099
2014	4795
2015	8140
2016	3758
2017	364
2018	369
2019	710
2020	750.01
2021	770
2022	1000