Year metric tons 1960 4196723 1961 5976151 1962 7761186 1963 7714751 1964 10012875 1965 8441272 1966 9854568 1967 11341571 1968 11810717 1969 10464882 1970 13980938 1971 12116130 1972 6435501 1973 4333220 1974 6063311 1975 5408968 1976 6450864 1977 4969737 1978 6564464 1979 6944815 1980 6170707 1981 6407922 1982 7183976 1983 4603391.9 1984 6936313.199999999 1985 8204831.42 1986 9739120.58 1987 8466336.58 1988 10552826.82 1989 10644389.8 1990 10195887.71 1991 10358678.49 1992 10725752.35 1993 12452139.379999999 1994 15579266.67 1995 12999954.58 1996 14024158.26 1997 12408403.86 1998 8059764.33 1999 12316416.63 2000 14663770.4 2001 12176476.5 2002 12795752.879999999 2003 9979000.05 2004 13455356.43 2005 13385259.51 2006 11419707.3 2007 11635566.49 2008 12091580.66 2009 11480900.83 2010 8643859 2011 12599582.899999999 2012 9006551.41 2013 10074966.49 2014 7932243.3 2015 8963867.979999999 2016 8017046.44 2017 8556954.2 2018 11657007.430000002 2019 9194004.709999999 2020 10032958.16 2021 11358169.740000004 2022 9959339.610000001