Year	metric tons
1960	800
1961	1000
1962	1000
1963	1000
1964	1000
1965	1200
1966	1200
1967	1200
1968	1200
1969	1200
1970	1300
1971	1300
1972	1300
1973	1700
1974	1625
1975	1449
1976	1368
1977	2004
1978	2688
1979	2704
1980	2906
1981	2800
1982	2241
1983	3477
1984	3669
1985	3024
1986	2333
1987	2390
1988	2756
1989	2923
1990	3072
1991	2872
1992	2885
1993	2935
1994	2886
1995	3063
1996	4537
1997	4368
1998	4313
1999	3850
2000	3979
2001	4414
2002	4029
2003	4210
2004	3976
2005	4155
2006	4128
2007	4357
2008	4200
2009	3673.6
2010	4503.2
2011	4067.1
2012	3837.24
2013	3821.13
2014	4300.75
2015	4343.2
2016	4484.65
2017	4108.2
2018	4669.6
2019	4428.2
2020	3180.72
2021	3332.51
2022	3480