Year	metric tons
1960	4671288
1961	6546433
1962	8546793
1963	8631844
1964	11361562
1965	9373065
1966	11492835
1967	12649795
1968	13444275
1969	11791033
1970	15443847
1971	13897489
1972	7535031
1973	5363577
1974	7532043
1975	6727042
1976	8311159
1977	6856131
1978	9025037
1979	10163867
1980	9674147
1981	10479900.79
1982	11589308.04
1983	9445042.05
1984	12269886.27
1985	14028444.24
1986	16157760.48
1987	14187911.61
1988	16650373.479999999
1989	18116035.41
1990	16406656.889999999
1991	17448183.03
1992	18297419.89
1993	19642737.32
1994	24673479.689999998
1995	22095142.06
1996	22451124.41
1997	20037115.45
1998	13265002.02
1999	19101513.73
2000	20882718
2001	18293030
2002	19487104.58
2003	16125003.05
2004	21199653.93
2005	20546001.060000002
2006	18411385.54
2007	18245376.53
2008	18597973.44
2009	17947006.790000003
2010	14145950.59
2011	18888242.03
2012	15015923.509999998
2013	15382838.17
2014	13947061.96
2015	14443422.010000002
2016	13225578.72
2017	14539618.230000002
2018	17809808.87
2019	15774040.45
2020	16624869.249999998
2021	18203441.329999994
2022	17240687.31