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 2 1976 4 1977 9 1978 13 1979 19 1980 27 1981 41 1982 58 1983 79 1984 185 1985 106 1986 106 1987 270 1988 399 1989 410 1990 573 1991 1975 1992 2244 1993 3335 1994 3910 1995 6756 1996 6986 1997 7000 1998 7937 1999 9324 2000 9708 2001 10520 2002 17892 2003 20546 2004 24708 2005 24038 2006 19962 2007 25765 2008 27059 2009 24754.3 2010 26839 2011 27713.5 2012 27287 2013 30352 2014 26765.5 2015 23559.5 2016 22212 2017 21124 2018 21955 2019 22046 2020 16268.95 2021 17309.4 2022 16772.41