Year	metric tons
1960	4809581
1961	5038072
1962	5236893
1963	5589218.1
1964	5937706.1
1965	6135414.4
1966	6170952.8
1967	6671096
1968	7313652
1969	6909611
1970	7047370
1971	7088516
1972	7199497
1973	7431739
1974	7967470
1975	7951201
1976	7894161
1977	7422408
1978	7259896.100000001
1979	7069212.7
1980	7632395.9
1981	7702130.649999999
1982	7948270.1
1983	8018137.619999999
1984	8072109.57
1985	8007684.33
1986	8087713
1987	7969823.16
1988	8306988.76
1989	8014292.9
1990	7146087.17
1991	7232685.850000001
1992	8049768.28
1993	7623212.27
1994	7951696.609999999
1995	8377423.049999999
1996	7782447.600000001
1997	7859471.89
1998	7713928.98
1999	7408134.6899999995
2000	7347741.39
2001	7428952.220000001
2002	6968979.04
2003	6565929.340000001
2004	6527110.32
2005	6300765.59
2006	6326168.16
2007	5944842.29
2008	5759687.75
2009	5858065.529999999
2010	5952580.369999999
2011	5655368.869999999
2012	5112038.52
2013	5448052.43
2014	5787063.78
2015	5786841.669999999
2016	5678511.75
2017	6073842.010000001
2018	5882772.999999999
2019	5369335.72
2020	5099260.269999999
2021	4881035.2299999995
2022	4778832.5200000005