Year metric tons 1960 303400 1961 346100 1962 321200 1963 361000 1964 388100 1965 377200 1966 353000 1967 314500 1968 323300 1969 323200 1970 300800 1971 321200 1972 348300 1973 343736 1974 325861 1975 350558 1976 284999 1977 313094 1978 324486 1979 323773 1980 340512 1981 479772 1982 544867 1983 561989 1984 496061 1985 554911 1986 502877 1987 511773 1988 476409 1989 530228 1990 507239 1991 458814 1992 487076 1993 532882 1994 529431 1995 522031 1996 510669 1997 550010 1998 656719 1999 623371 2000 571005 2001 575205 2002 518465 2003 592821 2004 600234 2005 626976 2006 558632 2007 544433 2008 487286.7 2009 442682.6 2010 501459.1 2011 413983.97000000003 2012 393488.4 2013 374057 2014 434451 2015 447120 2016 432284 2017 551818 2018 465199 2019 366791.8 2020 347466.11 2021 340231 2022 338052