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	10000
1988	10000
1989	11000
1990	12490
1991	12990
1992	17925
1993	19000
1994	20000
1995	21000
1996	22000
1997	28000
1998	28000
1999	28000
2000	28000
2001	25000
2002	24200
2003	23400
2004	22600
2005	21800
2006	21000
2007	20200
2008	19400
2009	18600
2010	17800
2011	17000
2012	17000
2013	17000
2014	17000
2015	17000
2016	17000
2017	17044.25
2018	17110.55
2019	16940.46
2020	16975
2021	17560
2022	17905