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	2
1980	4
1981	11
1982	45
1983	37
1984	47
1985	85
1986	142
1987	180
1988	198
1989	210
1990	212
1991	176
1992	187
1993	211
1994	215
1995	216
1996	220
1997	220
1998	220
1999	230
2000	232
2001	232
2002	233
2003	160
2004	160
2005	160
2006	162
2007	162
2008	162
2009	140.5
2010	129
2011	111
2012	111
2013	110
2014	110
2015	110
2016	110
2017	100
2018	103
2019	105
2020	108
2021	105
2022	108