Month Millions Of Net Ton-Miles 1931-01-01 671.000 1931-02-01 620.000 1931-03-01 701.000 1931-04-01 663.000 1931-05-01 699.000 1931-06-01 643.000 1931-07-01 656.000 1931-08-01 650.000 1931-09-01 669.000 1931-10-01 712.000 1931-11-01 684.000 1931-12-01 616.000 1932-01-01 627.000 1932-02-01 608.000 1932-03-01 628.000 1932-04-01 598.000 1932-05-01 607.000 1932-06-01 585.000 1932-07-01 562.000 1932-08-01 557.000 1932-09-01 567.000 1932-10-01 616.000 1932-11-01 609.000 1932-12-01 458.000 1933-01-01 550.000 1933-02-01 533.000 1933-03-01 628.000 1933-04-01 591.000 1933-05-01 634.000 1933-06-01 592.000 1933-07-01 609.000 1933-08-01 625.000 1933-09-01 648.000 1933-10-01 709.000 1933-11-01 704.000 1933-12-01 640.000 1934-01-01 671.000 1934-02-01 642.000 1934-03-01 714.000 1934-04-01 672.000 1934-05-01 707.000 1934-06-01 665.000 1934-07-01 666.000 1934-08-01 677.000 1934-09-01 696.000 1934-10-01 752.000 1934-11-01 722.000 1934-12-01 648.000 1935-01-01 683.000 1935-02-01 637.000 1935-03-01 717.000 1935-04-01 677.000 1935-05-01 692.000 1935-06-01 683.000 1935-07-01 677.000 1935-08-01 684.000 1935-09-01 700.000 1935-10-01 774.000 1935-11-01 754.000 1935-12-01 681.000 1936-01-01 698.000 1936-02-01 699.000 1936-03-01 778.000 1936-04-01 741.000 1936-05-01 778.000 1936-06-01 737.000 1936-07-01 728.000 1936-08-01 748.000 1936-09-01 760.000 1936-10-01 828.000 1936-11-01 782.000 1936-12-01 759.000 1937-01-01 744.000 1937-02-01 707.000 1937-03-01 807.000 1937-04-01 784.000 1937-05-01 815.000 1937-06-01 799.000 1937-07-01 780.000 1937-08-01 799.000 1937-09-01 822.000 1937-10-01 861.000 1937-11-01 814.000 1937-12-01 774.000 1938-01-01 762.000 1938-02-01 726.000 1938-03-01 802.000 1938-04-01 732.000 1938-05-01 714.000 1938-06-01 669.000 1938-07-01 632.000 1938-08-01 648.000 1938-09-01 671.000 1938-10-01 730.000 1938-11-01 683.000 1938-12-01 664.000 1939-01-01 646.000 1939-02-01 663.000 1939-03-01 773.000 1939-04-01 752.000