Year metric tons 1960 0 1961 0 1962 0 1963 0 1964 0 1965 0 1966 0 1967 0 1968 0 1969 0 1970 100 1971 100 1972 200 1973 200 1974 98 1975 66 1976 81 1977 146 1978 123 1979 92 1980 149 1981 136 1982 124 1983 0 1984 39 1985 36 1986 34 1987 34 1988 43 1989 11 1990 7 1991 12 1992 11 1993 26 1994 42 1995 60 1996 78 1997 74 1998 23 1999 155 2000 104 2001 105 2002 109 2003 98 2004 52 2005 54 2006 45 2007 45 2008 54 2009 71 2010 79.6 2011 334.67 2012 399.3 2013 706.8 2014 1012 2015 1212.5 2016 2078.83 2017 1010.7 2018 1108 2019 1010 2020 1100 2021 1150.5 2022 1585.1