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	3185
1994	3955
1995	3929
1996	3524
1997	3321
1998	3952
1999	4190
2000	4654
2001	4646
2002	4983
2003	5127
2004	4528
2005	4242
2006	4646
2007	4276
2008	4164
2009	4112
2010	3990
2011	3859
2012	4033
2013	3761
2014	3812
2015	3841
2016	3507
2017	3557
2018	3650
2019	3721
2020	3729
2021	3314
2022	3381