Year	metric tons
1960	250769
1961	264503
1962	274795
1963	283773
1964	298833
1965	310648
1966	328116
1967	345670
1968	381834
1969	397948
1970	420188
1971	450596
1972	477248
1973	516505
1974	571545
1975	605367
1976	654852
1977	724927
1978	843439
1979	939054
1980	1087010
1981	1210130
1982	1339509
1983	1512887
1984	1630186
1985	1770821
1986	1894107
1987	2191506
1988	2409636
1989	2601151
1990	2763414
1991	3060058
1992	3382563
1993	3533318
1994	3770609
1995	4115852
1996	4530410
1997	4686566
1998	4889276
1999	5430792
2000	5564256
2001	6123486
2002	6603444
2003	7231296
2004	8564267.2
2005	9819611.92
2006	10882247.8
2007	11753229.05
2008	13646833.860000001
2009	14780194.300000003
2010	17094368.759999998
2011	19120909.14
2012	21668020.48
2013	25863954.380000003
2014	27644648.51
2015	29680262.01
2016	30770908.849999998
2017	31824012.68
2018	33244160.81
2019	34070545.74
2020	34618889.61
2021	35128568.76
2022	36014991.56