Year	metric tons
1960	18929324
1961	20297290
1962	20990587
1963	21348161.1
1964	22118530.1
1965	23670319.4
1966	25222472.8
1967	26226829
1968	27521886
1969	26498172
1970	28420347
1971	29672259
1972	29704777
1973	30650281
1974	31553263
1975	30949580
1976	33111222
1977	33307657
1978	34125567.1
1979	34887988.7
1980	36125856.9
1981	38119709.16
1982	37976962.26
1983	39183138.22
1984	41696278.43
1985	41604112.37
1986	43726251.18000001
1987	43531102.29
1988	44520874.71999999
1989	44358887.760000005
1990	41404286.55
1991	40339669.96000001
1992	42145138.419999994
1993	41188361.08
1994	42795837.34
1995	42392642.800000004
1996	41421488.669999994
1997	41488934.379999995
1998	36646148.160000004
1999	38203370.04000001
2000	37014862.69
2001	37118529.8
2002	36956309.769999996
2003	35790419.29
2004	36749098.68
2005	35784990.46
2006	35468359.62
2007	35388532.809999995
2008	34424815.26
2009	34045222.940000005
2010	33186769.929999996
2011	33658174.70999999
2012	32910271.409999993
2013	32181696.080000006
2014	33082911.299999997
2015	32719741.230000004
2016	31265383.899999995
2017	33586483.93000001
2018	33620084.6
2019	33114134.320000008
2020	32114694.47
2021	32412338.619999994
2022	28059126.060000002