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 0 1972 0 1973 0 1974 0 1975 0 1976 0 1977 0 1978 0 1979 0 1980 0 1981 0 1982 0 1983 0 1984 3 1985 3 1986 2 1987 2 1988 1 1989 1 1990 1 1991 1 1992 5 1993 5 1994 5 1995 4 1996 4 1997 0 1998 0 1999 0 2000 0 2001 0 2002 2 2003 2 2004 2 2005 100 2006 110 2007 110 2008 170 2009 177 2010 185 2011 187.2 2012 292.5 2013 322.8 2014 351 2015 409 2016 477.8 2017 572.9 2018 686.6 2019 806.2 2020 1135 2021 1150 2022 1180