Year	metric tons
1960	830
1961	830
1962	1360
1963	1460
1964	1460
1965	1460
1966	1460
1967	1560
1968	1560
1969	1560
1970	1230
1971	1230
1972	1430
1973	1430
1974	1759
1975	3299
1976	4064
1977	2464
1978	3609
1979	4662
1980	3598
1981	2628
1982	2734
1983	3967
1984	3547
1985	4608
1986	5266
1987	2942
1988	3735
1989	3878
1990	2773
1991	3300
1992	3081
1993	4632
1994	4346
1995	5482
1996	5447
1997	4100
1998	5082
1999	5811.1
2000	6400.6
2001	5807.5
2002	5154.7
2003	5706
2004	5510
2005	6050
2006	4864
2007	6136
2008	6804
2009	5446.9
2010	3801.5
2011	3327.5
2012	1960.5
2013	2013.5
2014	2361.5
2015	2917.5
2016	3145.5
2017	1324.5
2018	2090.5
2019	1243
2020	1297
2021	2277