Year	metric tons
1960	489781
1961	517403
1962	533385
1963	558368
1964	601929
1965	566143
1966	522866
1967	583161
1968	527572
1969	480362
1970	477628
1971	453740
1972	458419
1973	492306
1974	442645
1975	387966
1976	352766
1977	313971
1978	259874
1979	251249
1980	276121
1981	269469
1982	259938
1983	255798
1984	311486
1985	327919
1986	413184
1987	397710
1988	353693
1989	340030
1990	337660
1991	337132
1992	306884
1993	301751
1994	276668
1995	272795
1996	270798
1997	234992
1998	236328
1999	218875
2000	199657
2001	202673
2002	211706
2003	220850
2004	229256
2005	227778
2006	237731
2007	264099
2008	231798
2009	205893.1
2010	231770.58
2011	225324.39
2012	209055.78999999998
2013	206625.56999999998
2014	195002.95
2015	199662.9
2016	196332.25
2017	195123.72
2018	192261.18000000002
2019	198739.84999999998
2020	180530.97
2021	199045.26
2022	180858.56