Year	metric tons
1960	11501285
1961	12566164
1962	13093306
1963	13136281
1964	13158241
1965	14077100
1966	14709764
1967	15820273
1968	17239100
1969	17468769
1970	18154673
1971	19468021
1972	20800488
1973	21695176
1974	22024095
1975	22163167
1976	22840414
1977	23686264
1978	23996546
1979	23392594
1980	23760463
1981	24871669.43
1982	25582040.919999998
1983	26611907.85
1984	27717532.279999997
1985	27646082.649999995
1986	29880405.87
1987	30879937.499999996
1988	31112261.549999997
1989	31403966.469999995
1990	31174926.02
1991	30766216.799999997
1992	31849951.78
1993	32677211.910000004
1994	33924263.519999996
1995	35437765.08
1996	36845590.71
1997	37665060.11
1998	37887205.480000004
1999	38121043.11
2000	37837468.10000001
2001	37519878.85
2002	37352598.37
2003	38472596.190000005
2004	38685316.26000001
2005	39019767.220000006
2006	39426677.71000001
2007	39963643.84000001
2008	39444262.760000005
2009	39012685.65999999
2010	39306795.59
2011	39536228.23
2012	39850405.94
2013	40415523.269999996
2014	41951355.43000001
2015	41913177.67999999
2016	40805352.77
2017	40810721.239999995
2018	40576213.519999996
2019	39788779.57000001
2020	38539612.35000001
2021	37833899.400000006
2022	36116269.65