Year metric tons 1960 7822578 1961 8227795 1962 8341651 1963 8759214.1 1964 9516754.1 1965 10733043.4 1966 11420465.8 1967 11999989 1968 11796369 1969 11254031 1970 11926735 1971 12067648 1972 12211701 1973 12491207 1974 12634036 1975 12416208 1976 13398952 1977 13309489 1978 12592808.100000001 1979 12511545.700000001 1980 12689844.9 1981 12782404.65 1982 12335901.100000001 1983 12821978.620000001 1984 13192412.66 1985 12939623.450000001 1986 12729283.129999999 1987 12784969.56 1988 13105849.56 1989 12350456.6 1990 11073009.87 1991 11027932.850000001 1992 19015619.48 1993 17579893.269999996 1994 16962312.61 1995 18376668.35 1996 18542587.299999997 1997 18931558.69 1998 18107692.48 1999 17277761.59 2000 17361656.39 2001 17053660.419999998 2002 16529752.84 2003 15662973.94 2004 15105452.83 2005 14884063.59 2006 14567656.059999999 2007 14645534.290000001 2008 14183991.200000003 2009 14396046.820000002 2010 14922515.809999999 2011 14446680.89 2012 14083351.67 2013 14522261.959999997 2014 14702094.929999998 2015 15232332.739999996 2016 14724643.85 2017 15983876.120000003 2018 16115022.550000003 2019 15211217.620000003 2020 15042973.28 2021 14820676.46 2022 14301021.209999999