Year	metric tons
1960	5925503
1961	6404993
1962	6519928
1963	6325257
1964	6001440
1965	6539879
1966	6735523
1967	7466503
1968	8138806
1969	8122882
1970	8747212
1971	9290197
1972	9617504
1973	9915271
1974	9899715
1975	9709486
1976	9771479
1977	9838729
1978	9844616
1979	9635205
1980	10062157
1981	10355590.43
1982	10437036.12
1983	10828994.46
1984	11589835.18
1985	10950837.33
1986	11479417.47
1987	11298495.82
1988	11351721.72
1989	10606200.17
1990	9771717.89
1991	8677929.46
1992	7961918.3
1993	7431353.41
1994	6767477.87
1995	6146892.92
1996	6097394.36
1997	6082181.11
1998	5430070.39
1999	5319633.24
2000	5191575.05
2001	4835571.5
2002	4501728.24
2003	4800065.75
2004	4451151.71
2005	4440914.2
2006	4451205.34
2007	4430071.55
2008	4441302.61
2009	4230700.65
2010	4188376.3
2011	3873951.41
2012	3756439.79
2013	3737616.38
2014	3735077.95
2015	3500278.52
2016	3296035.27
2017	3276568.5
2018	3380907.35
2019	3260033.47
2020	3267503.22
2021	3254272.68
2022	2967756.2