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 1 1978 5 1979 15 1980 16 1981 25 1982 30 1983 24 1984 42 1985 53 1986 50 1987 72 1988 73 1989 82 1990 78 1991 86 1992 100 1993 110 1994 142 1995 176 1996 165 1997 118 1998 83 1999 85 2000 87 2001 59 2002 56 2003 33 2004 350 2005 400 2006 443 2007 175 2008 245 2009 437.4 2010 567.5 2011 537.3 2012 512 2013 397.3 2014 777.5 2015 775.99 2016 1021.32 2017 1253.52 2018 2069.6 2019 3251.2 2020 3298 2021 2315.52 2022 1545.3