Year	metric tons
1960	4551326
1961	4975668
1962	5306517
1963	5492687
1964	5751528
1965	6040762
1966	6345563
1967	6601391
1968	7140524
1969	7311365
1970	7411949
1971	7940212
1972	8593405
1973	8897248
1974	8942545
1975	9107472
1976	9418770
1977	10198771
1978	10109481
1979	9691908
1980	9710826
1981	10129266
1982	10796969
1983	11628460.99
1984	11767930.14
1985	12267082.1
1986	13454935.590000002
1987	14536859.690000001
1988	14905937.65
1989	15670258.58
1990	16480230.329999998
1991	17616788.939999998
1992	19148820.68
1993	20511674.500000004
1994	22517590.099999998
1995	24602865.16
1996	26230417.349999998
1997	26994744.919999998
1998	28009134.75
1999	28354874.470000003
2000	28555437.830000002
2001	28484608.25
2002	28899809.970000003
2003	29708888.58
2004	30475384.330000002
2005	30710512.529999997
2006	31157023.85
2007	31396450.349999998
2008	30991190.41
2009	31127551.02
2010	31500001.650000002
2011	31976677.209999997
2012	32504503.009999998
2013	33147332.779999997
2014	34398163.96
2015	34794478.22
2016	34412972.72
2017	34471896.45
2018	34053100.26000001
2019	33427377.78
2020	32396176.769999996
2021	31711064.27
2022	31910120.62