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	31777
1993	16080
1994	15140
1995	9740
1996	9014
1997	8179
1998	7014
1999	9058
2000	12228
2001	12749
2002	12812
2003	14543
2004	14992
2005	15000
2006	15000
2007	15000
2008	15000
2009	15000
2010	15000
2011	15000
2012	15000
2013	15000
2014	15000
2015	15000
2016	15000
2017	15000
2018	15000
2019	15000
2020	14605
2021	15042
2022	15097