Year	metric tons
1960	5170150
1961	5736712
1962	6443995
1963	6686888
1964	7544215
1965	7575328
1966	8572776
1967	8207279
1968	8728140
1969	8643701
1970	8873086
1971	9670297
1972	9786943
1973	10399320
1974	10922677
1975	10991413
1976	11742829
1977	12638578
1978	13602300.9
1979	13941198.8
1980	13992874.1
1981	15155882.29
1982	15413847.04
1983	16244647.219999999
1984	17648172.73
1985	18503141.45
1986	20304719.51
1987	20622268.54
1988	21078126.040000003
1989	22378077.8
1990	21170692.569999997
1991	22296555.259999998
1992	30513305.88
1993	30297210.12
1994	33177136.69
1995	35655338.21
1996	36981318.07
1997	36745465.970000006
1998	34081234.66
1999	35714649.18000001
2000	35175002.35
2001	34055197.19
2002	34322847.76
2003	33680498.82
2004	35014420.93
2005	34526557.36
2006	33954347.239999995
2007	33656414.989999995
2008	33091471.45
2009	33637820.32
2010	33047109.74
2011	33775681.75000001
2012	34200791.22
2013	33928503.71
2014	34760940.949999996
2015	34871839.99
2016	34539213.72
2017	35039996.2
2018	34917682.44
2019	34188200.44
2020	33276217.21
2021	33457673.539999995
2022	33539617.889999993