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 0 1985 0 1986 0 1987 0 1988 0 1989 0 1990 0 1991 0 1992 0 1993 0 1994 0 1995 0 1996 0 1997 0 1998 13 1999 0 2000 0 2001 0 2002 0 2003 352 2004 515.4 2005 218 2006 114 2007 96 2008 121 2009 118.4 2010 127 2011 157 2012 168 2013 353 2014 282.4 2015 170 2016 103 2017 77.25 2018 451.45 2019 1054 2020 1307 2021 1703 2022 3468