Month	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