Year	metric tons
1961	6696635
1962	7089341
1963	7458814
1964	5838900
1965	5844000
1966	6183711
1967	11867534
1968	7003409
1969	7050700
1970	8137697
1971	11027700
1972	11950910
1973	6467880
1974	13579863
1975	11557896
1976	10273015
1977	12302690
1978	12755400
1979	11201720
1980	13377880
1981	18004771
1982	11762871
1983	6673572
1984	7927492
1985	11062037
1986	11691051
1987	12096954
1988	12140142
1989	15341300
1990	11558395
1991	11292510.68
1992	5056342.22
1993	12805479.03
1994	15985688.36
1995	7514386.6
1996	13670069.97
1997	13254451.26
1998	10232322.97
1999	10059495.21
2000	14549008.85
2001	10714748.18
2002	13048224.68
2003	11819152.78
2004	12026898.78
2005	14175144.28
2006	9452299.88
2007	9507863.32
2008	15339478.04
2009	14570877.03
2010	14700930.93
2011	12928365.21
2012	14556167.9
2013	14154567.74
2014	16617348.61
2015	12581802.08
2016	10629626.27
2017	19591509.64
2018	15565749.67
2019	13872312.71
2020	18790392.17
2021	19865089.53
2022	18685897.57