Year	metric tons
1960	360000
1961	360000
1962	360000
1963	360000
1964	360000
1965	360000
1966	360000
1967	380700
1968	396100
1969	413900
1970	431670
1971	441840
1972	452300
1973	462240
1974	432510
1975	483620
1976	499830
1977	516730
1978	537470
1979	561570
1980	577220
1981	591420
1982	580950
1983	583710
1984	609740
1985	643750
1986	680718
1987	680371
1988	698874
1989	726816
1990	736731
1991	726672
1992	731544
1993	739702
1994	746241
1995	751710
1996	602280
1997	780800
1998	830650
1999	920010
2000	1093200
2001	1187880
2002	1284340
2003	1343860
2004	1586600
2005	1732250
2006	1823450
2007	1907750
2008	1907010
2009	1892600
2010	1961150
2011	1975920
2012	1962231
2013	1919001
2014	1970550
2015	1970470
2016	2072390
2017	2155440
2018	2036869
2019	1951120
2020	1977330
2021	1665740
2022	1864730