Year	metric tons
1960	489781
1961	517403
1962	533385
1963	558368
1964	601929
1965	566142
1966	522863
1967	583153
1968	527556
1969	480338
1970	477581
1971	453661
1972	458300
1973	492151
1974	442442
1975	387734
1976	352501
1977	313662
1978	259480
1979	250760
1980	275522
1981	268787
1982	259099
1983	253335
1984	305246
1985	321517
1986	402853
1987	386698
1988	343260
1989	331481
1990	332692
1991	330855
1992	300482
1993	295781
1994	270130
1995	267814
1996	265434
1997	227807
1998	228792
1999	212607
2000	192120
2001	194464
2002	203418
2003	212817
2004	222556
2005	221082
2006	229837
2007	256683
2008	224446
2009	199165
2010	223546
2011	216159
2012	198737.99
2013	196558.36
2014	183664
2015	190100.02
2016	186545.01
2017	182614.98
2018	178270.01
2019	185049.08
2020	159947.96
2021	179528.78
2022	159890.56