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	0
1993	20242
1994	18655
1995	18679
1996	18200
1997	17560
1998	17231
1999	18775
2000	19475
2001	20098
2002	19210
2003	19670
2004	19384
2005	20455
2006	20431
2007	20447
2008	20395
2009	20071
2010	20420
2011	21010
2012	20763
2013	19357.4
2014	20135
2015	20200
2016	20952
2017	21685
2018	21751
2019	20986
2020	20401
2021	20991
2022	19259