Year metric tons 1960 8044825 1961 8460059 1962 8619266 1963 9055794.1 1964 9834731.1 1965 11063136.4 1966 11726667.8 1967 12308386 1968 12160498 1969 11626619 1970 12344735 1971 12474677 1972 12711191 1973 12988080 1974 13154573 1975 12994022 1976 13963438 1977 13931136 1978 13246258.100000001 1979 13123373.700000001 1980 13306337.9 1981 13463841.65 1982 13085405.100000001 1983 13601789.62 1984 14002010.66 1985 13828030.450000001 1986 13643433.129999999 1987 13728730.56 1988 14098887.56 1989 13319190.600000001 1990 12135106.870000001 1991 12134904.850000001 1992 20293257.48 1993 18863670.269999996 1994 18361247.61 1995 19873456.35 1996 20136482.3 1997 20619223.69 1998 19968515.48 1999 19258205.59 2000 19340563.39 2001 19057659.419999998 2002 18441309.6 2003 17732275.040000003 2004 17170419.23 2005 16913615.59 2006 16652006.31 2007 16935447.490000002 2008 16439690.72 2009 16876715.449999996 2010 17422891.459999997 2011 17090645.26 2012 16931376.220000003 2013 17276521.580000002 2014 17620430.71 2015 18218004.41 2016 17741353.699999996 2017 19058974.14 2018 19299255.14 2019 18690121.119999997 2020 18611359.800000004 2021 18755161.369999997 2022 18002738.750000004