Year metric tons 1960 0 1961 0 1962 0 1963 0 1964 0 1965 0 1966 0 1967 0 1968 0 1969 0 1970 0 1971 5 1972 10 1973 20 1974 20 1975 20 1976 20 1977 20 1978 24 1979 27 1980 31 1981 47 1982 56 1983 70 1984 40 1985 280 1986 430 1987 530 1988 699 1989 730 1990 1030 1991 1530 1992 2030 1993 2530 1994 3130 1995 3359 1996 3632 1997 3680 1998 6570 1999 3900 2000 4420 2001 3610 2002 2651 2003 3462 2004 4003 2005 4304 2006 5652 2007 8233 2008 7474 2009 7548.68 2010 8058.14 2011 11912.22 2012 8839.76 2013 30881.3 2014 34220.3 2015 36037.75 2016 30974.22 2017 28756.16 2018 30921.46 2019 34087.49 2020 42118.9 2021 50977.22 2022 59080.29