Year	metric tons
1960	0
1961	0
1962	0
1963	16
1964	24
1965	32
1966	48
1967	72
1968	96
1969	128
1970	160
1971	216
1972	272
1973	344
1974	432
1975	536
1976	664
1977	808
1978	984
1979	1184
1980	1408
1981	1680
1982	1984
1983	2328
1984	2500
1985	4000
1986	5000
1987	6000
1988	7000
1989	8000
1990	10000
1991	10500
1992	10760
1993	11000
1994	11200
1995	12880
1996	16000
1997	21143
1998	21216
1999	30362
2000	42066
2001	50000
2002	59716
2003	64900
2004	64900
2005	60000
2006	60000
2007	63250
2008	64300
2009	75000.5
2010	82100
2011	95600
2012	101895
2013	103900
2014	90360
2015	95965
2016	106600
2017	109800
2018	118700
2019	123000
2020	130020
2021	135008