Year metric tons 1960 257300 1961 246800 1962 274800 1963 245300 1964 362000 1965 263300 1966 335300 1967 299300 1968 303100 1969 425200 1970 374501 1971 324322 1972 606656 1973 478659 1974 399784 1975 160581 1976 81542 1977 120407 1978 125630 1979 113072 1980 85085 1981 130957 1982 111488 1983 110376 1984 95188 1985 100093 1986 84660 1987 107490 1988 126031 1989 137465 1990 133088 1991 117104 1992 113625 1993 126200 1994 132413 1995 122781 1996 137815 1997 146304 1998 163149 1999 175799 2000 239351 2001 254553 2002 255443 2003 212033 2004 240002 2005 202616 2006 225741 2007 306436 2008 305860 2009 272042 2010 310000 2011 342000 2012 374000 2013 407000 2014 442084 2015 495232 2016 486490 2017 531575 2018 443066 2019 399762 2020 374453 2021 528714 2022 469336