Year	metric tons
1960	3000
1961	3000
1962	3000
1963	3200
1964	3400
1965	3500
1966	3500
1967	3500
1968	3800
1969	3800
1970	3900
1971	3900
1972	4700
1973	4700
1974	4800
1975	5036
1976	5589
1977	7935
1978	9250
1979	20243
1980	20404
1981	23608
1982	24931
1983	24227
1984	25639
1985	26870
1986	35100.4
1987	38670.5
1988	34209
1989	35520.3
1990	39528.77
1991	33011.380000000005
1992	27687.100000000002
1993	30646.03
1994	30300
1995	30507
1996	26877
1997	30086
1998	33075.61
1999	56066.020000000004
2000	49357
2001	50033
2002	41526
2003	37631.8
2004	50194.16
2005	47951.5
2006	50351
2007	48077
2008	47483
2009	47057.03
2010	42710.5
2011	47553
2012	47467
2013	43010
2014	44391
2015	41954
2016	45011
2017	47745
2018	43029.41
2019	42003.87
2020	37919.420000000006
2021	33215.58
2022	32837.2