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	4450
1993	4100
1994	2603
1995	1941
1996	1230
1997	1250
1998	1135
1999	2033
2000	2026
2001	2197
2002	1485
2003	1633
2004	1031
2005	989
2006	1406
2007	4715
2008	5701
2009	5809
2010	5667
2011	7095
2012	9711
2013	15799
2014	18720
2015	23270
2016	20139
2017	17054
2018	17369
2019	18270
2020	19100.01
2021	19700
2022	25000