Year	metric tons
1960	600
1961	600
1962	600
1963	700
1964	700
1965	700
1966	700
1967	800
1968	1000
1969	1400
1970	1800
1971	2200
1972	2500
1973	2700
1974	2700
1975	2800
1976	2900
1977	3000
1978	3100
1979	3200
1980	3300
1981	3350
1982	3400
1983	3500
1984	5000
1985	7500
1986	13000
1987	10022
1988	10054
1989	11051
1990	12551
1991	13050
1992	18000
1993	19075
1994	20100
1995	21190
1996	22350
1997	28350
1998	28095
1999	28095
2000	28103
2001	25570
2002	25200
2003	24700
2004	24700
2005	23920
2006	23250
2007	22550
2008	21850
2009	21200
2010	20757.42
2011	21929.06
2012	22400
2013	23450
2014	24500
2015	25481
2016	25500
2017	27825.25
2018	28646.55
2019	29690.46
2020	31075
2021	31710
2022	37905