Year	metric tons
1960	900
1961	500
1962	800
1963	1000
1964	1000
1965	600
1966	1200
1967	1100
1968	3700
1969	3500
1970	4000
1971	4000
1972	4000
1973	4000
1974	4000
1975	4000
1976	4000
1977	4000
1978	4000
1979	4000
1980	2500
1981	2500
1982	2019
1983	2341
1984	4000
1985	3600
1986	4400
1987	4000
1988	4000
1989	4000
1990	3700
1991	3500
1992	3600
1993	3507
1994	5069
1995	2306
1996	5040
1997	6090
1998	6005
1999	7001
2000	3634
2001	3600
2002	3550
2003	3550
2004	3500
2005	3750
2006	4002
2007	4535
2008	5402
2009	7672
2010	7391
2011	7132
2012	7849
2013	6941.15
2014	6082.92
2015	6438.26
2016	6470.29
2017	6392
2018	6422.61
2019	6432.72
2020	5973.28
2021	6322.12
2022	6625.15