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 1045 1993 580 1994 228 1995 157 1996 101 1997 61 1998 96 1999 83 2000 86 2001 80 2002 52 2003 56 2004 72 2005 107 2006 150 2007 180 2008 422 2009 705 2010 850 2011 1000 2012 1155 2013 1305 2014 1495 2015 1655 2016 1805 2017 2042 2018 2381.5 2019 2444.7 2020 2026.9 2021 2790.4 2022 2743.2