Monthly Thousands Of Hours
1921-07-01 1056.00
1921-08-01 1064.00
1921-09-01 1008.00
1921-10-01 963.000
1921-11-01 937.000
1921-12-01 992.000
1922-01-01 959.000
1922-02-01 886.000
1922-03-01 957.000
1922-04-01 889.000
1922-05-01 943.000
1922-06-01 954.000
1922-07-01 1064.00
1922-08-01 1139.00
1922-09-01 1091.00
1922-10-01 1044.00
1922-11-01 1024.00
1922-12-01 1153.00
1923-01-01 1119.00
1923-02-01 1034.00
1923-03-01 1103.00
1923-04-01 968.000
1923-05-01 1007.00
1923-06-01 975.000
1923-07-01 1050.00
1923-08-01 1070.00
1923-09-01 1004.00
1923-10-01 1018.00
1923-11-01 954.000
1923-12-01 1001.00
1924-01-01 1030.00
1924-02-01 933.000
1924-03-01 953.000
1924-04-01 916.000
1924-05-01 938.000
1924-06-01 914.000
1924-07-01 963.000
1924-08-01 965.000
1924-09-01 910.000
1924-10-01 896.000
1924-11-01 834.000
1924-12-01 975.000
1925-01-01 954.000
1925-02-01 818.000
1925-03-01 856.000
1925-04-01 833.000
1925-05-01 840.000
1925-06-01 854.000
1925-07-01 909.000
1925-08-01 903.000
1925-09-01 859.000
1925-10-01 869.000
1925-11-01 826.000
1925-12-01 911.000
1926-01-01 842.000
1926-02-01 813.000
1926-03-01 846.000
1926-04-01 800.000
1926-05-01 796.000
1926-06-01 808.000
1926-07-01 868.000
1926-08-01 858.000
1926-09-01 828.000
1926-10-01 808.000
1926-11-01 786.000
1926-12-01 884.000
1927-01-01 815.000
1927-02-01 729.000
1927-03-01 797.000
1927-04-01 770.000
1927-05-01 766.000
1927-06-01 769.000
1927-07-01 803.000
1927-08-01 821.000
1927-09-01 768.000
1927-10-01 748.000
1927-11-01 733.000
1927-12-01 807.000
1928-01-01 747.000
1928-02-01 688.000
1928-03-01 733.000
1928-04-01 693.000
1928-05-01 712.000
1928-06-01 710.000
1928-07-01 742.000
1928-08-01 773.000
1928-09-01 703.000
1928-10-01 711.000
1928-11-01 676.000
1928-12-01 711.000
1929-01-01 716.000
1929-02-01 636.000
1929-03-01 695.000
1929-04-01 664.000
1929-05-01 677.000
1929-06-01 659.000
1929-07-01 706.000
1929-08-01 711.000
1929-09-01 658.000
1929-10-01 678.000
1929-11-01 629.000
1929-12-01 718.000
1930-01-01 673.000
1930-02-01 584.000
1930-03-01 639.000
1930-04-01 617.000
1930-05-01 628.000
1930-06-01 615.000
1930-07-01 647.000
1930-08-01 637.000
1930-09-01 587.000
1930-10-01 585.000
1930-11-01 530.000
1930-12-01 581.000
1931-01-01 557.000
1931-02-01 497.000
1931-03-01 548.000
1931-04-01 526.000
1931-05-01 522.000
1931-06-01 523.000
1931-07-01 555.000
1931-08-01 528.000
1931-09-01 489.000
1931-10-01 465.000
1931-11-01 426.000
1931-12-01 465.000
1932-01-01 429.000
1932-02-01 405.000
1932-03-01 438.000
1932-04-01 379.000
1932-05-01 397.000
1932-06-01 396.000
1932-07-01 402.000
1932-08-01 409.000
1932-09-01 375.000
1932-10-01 360.000
1932-11-01 345.000
1932-12-01 380.000
1933-01-01 348.000
1933-02-01 320.000
1933-03-01 351.000
1933-04-01 325.000
1933-05-01 338.000
1933-06-01 347.000
1933-07-01 348.000
1933-08-01 365.000
1933-09-01 337.000
1933-10-01 328.000
1933-11-01 309.000
1933-12-01 348.000
1934-01-01 331.000
1934-02-01 323.000
1934-03-01 334.000
1934-04-01 313.000
1934-05-01 326.000
1934-06-01 327.000
1934-07-01 352.000
1934-08-01 364.000
1934-09-01 323.000
1934-10-01 333.000
1934-11-01 309.000
1934-12-01 337.000
1935-01-01 370.000
1935-02-01 298.000
1935-03-01 318.000
1935-04-01 313.000
1935-05-01 323.000
1935-06-01 316.000
1935-07-01 342.000
1935-08-01 350.000
1935-09-01 314.000
1935-10-01 327.000
1935-11-01 307.000
1935-12-01 349.000
1936-01-01 356.000
1936-02-01 371.000
1936-03-01 366.000
1936-04-01 330.000
1936-05-01 320.000
1936-06-01 328.000
1936-07-01 362.000
1936-08-01 351.000
1936-09-01 335.000
1936-10-01 341.000
1936-11-01 316.000
1936-12-01 371.000
1937-01-01 358.000
1937-02-01 328.000
1937-03-01 348.000
1937-04-01 331.000
1937-05-01 329.000
1937-06-01 343.000
1937-07-01 364.000
1937-08-01 362.000
1937-09-01 339.000
1937-10-01 328.000
1937-11-01 315.000
1937-12-01 363.000
1938-01-01 331.000
1938-02-01 297.000
1938-03-01 333.000
1938-04-01 311.000
1938-05-01 306.000
1938-06-01 314.000
1938-07-01 321.000
1938-08-01 324.000
1938-09-01 319.000
1938-10-01 300.000
1938-11-01 291.000
1938-12-01 325.000
1939-01-01 294.000
1939-02-01 267.000
1939-03-01 298.000
1939-04-01 275.000
1939-05-01 296.000
1939-06-01 302.000
1939-07-01 312.000
1939-08-01 330.000
1939-09-01 304.000
1939-10-01 300.000
1939-11-01 278.000
1939-12-01 310.000
1940-01-01 311.000
1940-02-01 283.000
1940-03-01 289.000
1940-04-01 283.000
1940-05-01 290.000
1940-06-01 287.000