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	0
1975	2
1976	8
1977	15
1978	23
1979	32
1980	43
1981	59
1982	80
1983	107
1984	137
1985	103
1986	273
1987	643
1988	1209
1989	1677
1990	2829
1991	2873
1992	2524
1993	2917
1994	3222
1995	3485
1996	3687
1997	3663
1998	3868
1999	3897
2000	3623
2001	4371
2002	3585
2003	6214
2004	8868
2005	8256
2006	8241
2007	4823
2008	5098
2009	5165
2010	5050
2011	5308.5
2012	7431.3
2013	7053
2014	8433.5
2015	8382.6
2016	15129
2017	20858.7
2018	19185
2019	34054.8
2020	40609
2021	53154
2022	51362