Year metric tons 1960 3836623.01 1961 3728664 1962 3979607 1963 4204150 1964 4848198 1965 4907514 1966 5231640.01 1967 5314155 1968 5611986 1969 5942303 1970 6198641 1971 6558221 1972 7036107 1973 7469485 1974 7432548 1975 7101746 1976 7005569 1977 7302135.99 1978 7357337.909999999 1979 7381484.81 1980 7447639.1 1981 7748798.08 1982 7860165.640000001 1983 8497024.28 1984 8755340.54 1985 8857721.58 1986 9402134.4 1987 9472414.91 1988 9809473.020000001 1989 10459603.41 1990 10893698.46 1991 11168584.419999998 1992 11857487.62 1993 12103826.93 1994 12517679.750000002 1995 13009696.400000002 1996 13131089.769999998 1997 13811149.93 1998 13986435.28 1999 14916874.539999997 2000 15601398.67 2001 16189482.56 2002 16162525.270000001 2003 16574873.7 2004 16793038.119999997 2005 17613318.12 2006 18041768.779999997 2007 18370309.36 2008 18860018.23 2009 19425338.93 2010 20212213.669999998 2011 19751058.11 2012 20976216.82 2013 21071802.219999995 2014 21975838.33 2015 21926568.359999992 2016 22985204.269999996 2017 24467886.49 2018 24267167.799999997 2019 24260907.33 2020 23053477.98 2021 23481457.229999993 2022 23504541.769999996