Year	metric tons
1961	716
1962	899
1963	708
1964	508
1965	560
1966	830
1967	1000
1968	1449
1969	1754
1970	1600
1971	1400
1972	2073
1973	2000
1974	2000
1975	2000
1976	2000
1977	2000
1978	2000
1979	2000
1980	2000
1981	2000
1982	2000
1983	2000
1984	2400
1985	2000
1986	2100
1987	2100
1988	2200
1989	2200
1990	2300
1991	2100
1992	1800
1993	1600
1994	1300
1995	1100
1996	800
1997	650
1998	520
1999	390
2000	300
2001	250
2002	218
2003	263
2004	250
2005	260
2006	270
2007	280
2008	267.8
2009	262.66
2010	259.58
2011	268.89
2012	320
2013	340
2014	81
2015	122
2016	95.57
2017	73.86
2018	109.3
2019	42
2020	86
2021	49.9
2022	51