Year metric tons 1960 2500 1961 2800 1962 2800 1963 3300 1964 2800 1965 2700 1966 3000 1967 3000 1968 3500 1969 3500 1970 2400 1971 2800 1972 3595 1973 3590 1974 3785 1975 3875 1976 3875 1977 3922 1978 3730 1979 3760 1980 3330 1981 3476 1982 3149 1983 3290 1984 3841 1985 4294 1986 4386 1987 4271 1988 3973 1989 3303 1990 3158 1991 3599 1992 2715 1993 1822 1994 1481 1995 1588 1996 1841 1997 1859 1998 1809 1999 1840 2000 1659 2001 1715 2002 1544 2003 1815 2004 1602 2005 1738 2006 1690 2007 1653 2008 2084 2009 2184 2010 2101 2011 2098 2012 2003 2013 2007 2014 1983 2015 2023 2016 1851 2017 1932 2018 1553 2019 1382.34 2020 1485.93 2021 1485.93 2022 1485.93