Year metric tons 1960 400 1961 400 1962 400 1963 500 1964 500 1965 500 1966 500 1967 500 1968 400 1969 500 1970 600 1971 300 1972 300 1973 200 1974 283 1975 549 1976 379 1977 581 1978 698 1979 547 1980 500 1981 500 1982 500 1983 480 1984 480 1985 483 1986 599 1987 703 1988 4647 1989 5820 1990 9022 1991 8167 1992 2171 1993 2240 1994 3922 1995 1033 1996 989 1997 6145 1998 34108 1999 17804 2000 22799 2001 31944 2002 46076 2003 37767 2004 78315 2005 44104 2006 51584 2007 63309 2008 55898 2009 59587 2010 66367 2011 76576 2012 10156.27 2013 39499.91 2014 81332.54 2015 26132.99 2016 22833.71 2017 32937.79 2018 2327.89 2019 1968.79 2020 2127.52 2021 1586.28