Year	metric tons
1960	4600
1961	5200
1962	5200
1963	6000
1964	7000
1965	6200
1966	5900
1967	5600
1968	5600
1969	5900
1970	6000
1971	7000
1972	8000
1973	9000
1974	9000
1975	9000
1976	11000
1977	13000
1978	15000
1979	17000
1980	19000
1981	21000
1982	24000
1983	25000
1984	27000
1985	41846
1986	45500
1987	46400
1988	52200
1989	60500
1990	61916
1991	61617
1992	63895
1993	51210
1994	56603
1995	71815
1996	91137
1997	85704
1998	139389
1999	226276
2000	340093
2001	342864
2002	376296
2003	445181
2004	471535
2005	539748
2006	595030
2007	635516
2008	693765
2009	705490
2010	919585
2011	986820
2012	1017738
2013	1097544
2014	1137091
2015	1174831
2016	1370660
2017	1406864.5
2018	1594231
2019	1641949
2020	1591896
2021	1576189.4
2022	1552430