Year	metric tons
1960	338564
1961	407113
1962	445299
1963	451522
1964	527254
1965	566483
1966	611608
1967	663431
1968	734954
1969	798519
1970	752551
1971	915674
1972	1178402
1973	1420581
1974	1680423
1975	1781172
1976	1992496
1977	1929422
1978	1957653
1979	1935815
1980	1863228
1981	2105368
1982	2038071
1983	2146033
1984	2228809
1985	2303047
1986	2708337
1987	2457850
1988	2317365
1989	2468774
1990	2496909
1991	2195470
1992	2348616
1993	2279380
1994	2385513
1995	2342340
1996	2437110
1997	2227791
1998	2040832
1999	2131618
2000	1838195
2001	2008995
2002	1704448
2003	1661787
2004	1589746
2005	1661761
2006	1772459
2007	1888362
2008	1970882
2009	1871904
2010	1735000
2011	1757193.59
2012	1673719.63
2013	1605307.22
2014	1751932.5
2015	1658005.13
2016	1371347.39
2017	1359547.23
2018	1402993.76
2019	1424965.84
2020	1376149.23
2021	1314889.31