Year	metric tons
1960	1000
1961	1300
1962	2100
1963	2500
1964	2700
1965	2100
1966	3000
1967	2500
1968	1900
1969	3000
1970	3400
1971	3300
1972	3100
1973	3700
1974	3881
1975	4530
1976	3653
1977	3074
1978	5504
1979	4898
1980	3507
1981	4265
1982	4284
1983	2376
1984	2963
1985	2707
1986	2119
1987	2426
1988	2805
1989	3614
1990	6894
1991	6513
1992	6578
1993	7582
1994	7211
1995	8253
1996	7653
1997	6896
1998	10847
1999	21018
2000	39203
2001	29704
2002	23427
2003	23696
2004	10012
2005	18979
2006	17569
2007	17965
2008	23291
2009	20149
2010	22332
2011	19844.51
2012	15291.25
2013	17686.39
2014	18075.6
2015	15153.76
2016	15981.69
2017	15375.72
2018	14075.13
2019	15714.26
2020	11489.61
2021	11082.06
2022	16256.64