Year	metric tons
1961	937596
1962	2369800
1963	2324215
1964	1487506
1965	1735461
1966	776122
1967	1641700
1968	2128233
1969	1852429
1970	2058094
1971	1735448
1972	2362625
1973	1595994
1974	1480275
1975	2680452
1976	2313186
1977	1142509
1978	1538550
1979	1620808
1980	2419074
1981	1832872
1982	1524398
1983	1290834
1984	1461484
1985	2918778
1986	2403612
1987	2066344
1988	1038303
1989	2006130
1990	1627035
1991	3809857
1992	3330382.14
1993	1453453.67
1994	964743.63
1995	2139705.48
1996	4901677.89
1997	870017
1998	3026097.49
1999	2021053.36
2000	934656.39
2001	2659594.68
2002	1953325.24
2003	4266387.06
2004	4033241.92
2005	3527824.19
2006	4018104.98
2007	3602256.33
2008	1536002.32
2009	5253472.23
2010	4211354.54
2011	4247535.01
2012	5137455
2013	4912551
2014	3435535
2015	3761229.6
2016	3445227.37
2017	3478175.14
2018	6066238.69
2019	5633592.07
2020	4393330.47
2021	2784008.92
2022	4718203.91