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 3899 1993 2907 1994 1874 1995 1714 1996 1537 1997 1516 1998 1516 1999 1650 2000 1996 2001 2001 2002 1750 2003 2356 2004 2697 2005 2013 2006 2224 2007 3377 2008 3008 2009 3421.6 2010 3190.99 2011 3279.61 2012 3581.96 2013 4210.88 2014 3835.8 2015 4450.17 2016 4392.74 2017 3749.07 2018 3744.43 2019 4214.65 2020 4477.45 2021 5135.34 2022 4859.01