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	10
1975	23
1976	27
1977	22
1978	24
1979	27
1980	23
1981	15
1982	19
1983	20
1984	13
1985	23
1986	25
1987	26
1988	30
1989	25
1990	20
1991	15
1992	17
1993	18
1994	18
1995	14
1996	14
1997	14
1998	8
1999	4
2000	8
2001	8
2002	8
2003	4
2004	2
2005	1
2006	2
2007	131
2008	91
2009	107.6
2010	300.4
2011	300.37
2012	400.37
2013	500.43
2014	900.53
2015	1001
2016	1050
2017	1801
2018	2500.46
2019	2550
2020	2601
2021	1501.3
2022	1836.26