Year metric tons 1960 4000 1961 4000 1962 5000 1963 5000 1964 5300 1965 5300 1966 7300 1967 7400 1968 7400 1969 7400 1970 8500 1971 13511 1972 17005 1973 15924 1974 19676 1975 16940 1976 26284 1977 22863 1978 29192 1979 35431 1980 34866 1981 34728 1982 32518 1983 46014.59 1984 48801.74 1985 43363 1986 56743.39 1987 43556.22 1988 51602.07 1989 50145.79 1990 41404.36 1991 63005.77 1992 47107.72 1993 43623.03 1994 47509.3 1995 64181.41 1996 52445.45 1997 61289.49 1998 60726.59 1999 54557.6 2000 19564.34 2001 24538.36 2002 26252.55 2003 36699.22 2004 35045.67 2005 30171.14 2006 39525.66 2007 32150.18 2008 27457.7 2009 28652.6 2010 37544.66 2011 38720.16 2012 38892.07 2013 36708.88 2014 70717.31 2015 67995.99 2016 65572.36 2017 49988 2018 62640.11 2019 68303.88 2020 40902.67 2021 49829.28 2022 47838.09