Year	metric tons
1960	500
1961	500
1962	500
1963	500
1964	700
1965	700
1966	700
1967	800
1968	800
1969	800
1970	900
1971	900
1972	800
1973	1000
1974	1368
1975	1198
1976	1008
1977	1325
1978	733
1979	974
1980	1223
1981	982
1982	1240
1983	1248
1984	825
1985	945
1986	1546
1987	1694
1988	1328
1989	1516
1990	2514
1991	3561
1992	3697
1993	3553
1994	3460
1995	3379
1996	3052
1997	4546
1998	6769
1999	6733
2000	6996
2001	7263
2002	7612
2003	8427
2004	8212
2005	6850.15
2006	7741.2
2007	9246.2
2008	11647.25
2009	11612.3
2010	13100.3
2011	17259.33
2012	19485.98
2013	23555.2
2014	26663
2015	30954.2
2016	26593
2017	28357
2018	27534
2019	24760.2
2020	37037.6
2021	42407.3
2022	44937