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 7728 1993 4358 1994 3095 1995 3611 1996 2200 1997 3075 1998 2799 1999 2908 2000 3306 2001 3400 2002 2600 2003 2100 2004 1900 2005 2900 2006 3400 2007 3100 2008 3800 2009 4100 2010 4078 2011 8513 2012 11052 2013 13670 2014 17116 2015 22956 2016 27267 2017 31450 2018 33600 2019 40000 2020 46100.02 2021 53000.01 2022 54999.98