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 23 1987 0 1988 0 1989 542 1990 99 1991 158 1992 301 1993 602 1994 656 1995 950 1996 1004 1997 1397 1998 1642 1999 3163 2000 3630 2001 4460 2002 4400 2003 10160 2004 11426 2005 11078 2006 7624 2007 3172 2008 4528 2009 5725 2010 7410.7 2011 5102 2012 5883.2 2013 7160 2014 7214.96 2015 4206 2016 1151 2017 565 2018 576 2019 579 2020 559 2021 609 2022 1130