Month	Thousands Of Hours
1920-01-01	1725.00
1920-02-01	1626.00
1920-03-01	1782.00
1920-04-01	1513.00
1920-05-01	1545.00
1920-06-01	1556.00
1920-07-01	1583.00
1920-08-01	1481.00
1920-09-01	1613.00
1920-10-01	1254.00
1920-11-01	1454.00
1920-12-01	1586.00
1921-01-01	1365.00
1921-02-01	1188.00
1921-03-01	1161.00
1921-04-01	641.000
1921-05-01	477.000
1921-06-01	530.000
1921-07-01	1008.00
1921-08-01	1221.00
1921-09-01	1169.00
1921-10-01	1192.00
1921-11-01	1271.00
1921-12-01	1235.00
1922-01-01	1215.00
1922-02-01	1184.00
1922-03-01	1317.00
1922-04-01	1080.00
1922-05-01	1206.00
1922-06-01	1048.00
1922-07-01	1176.00
1922-08-01	1269.00
1922-09-01	1302.00
1922-10-01	1350.00
1922-11-01	1429.00
1922-12-01	1324.00
1923-01-01	1427.00
1923-02-01	1337.00
1923-03-01	1463.00
1923-04-01	1303.00
1923-05-01	1365.00
1923-06-01	1341.00
1923-07-01	1316.00
1923-08-01	1355.00
1923-09-01	1354.00
1923-10-01	1526.00
1923-11-01	1567.00
1923-12-01	1522.00
1924-01-01	1325.00
1924-02-01	1638.00
1924-03-01	1672.00
1924-04-01	1457.00
1924-05-01	1475.00
1924-06-01	1232.00
1924-07-01	1427.00
1924-08-01	1338.00
1924-09-01	1454.00
1924-10-01	1560.00
1924-11-01	1461.00
1924-12-01	1509.00
1925-01-01	1553.00
1925-02-01	1409.00
1925-03-01	1471.00
1925-04-01	1298.00
1925-05-01	1308.00
1925-06-01	1226.00
1925-07-01	1515.00
1925-08-01	1288.00
1925-09-01	1373.00
1925-10-01	1512.00
1925-11-01	1524.00
1925-12-01	1674.00
1926-01-01	1590.00
1926-02-01	1514.00
1926-03-01	1640.00
1926-04-01	1416.00
1926-05-01	428.000
1926-06-01	725.000
1926-07-01	791.000
1926-08-01	838.000
1926-09-01	942.000
1926-10-01	1180.00
1926-11-01	1424.00
1926-12-01	1699.00
1927-01-01	1747.00
1927-02-01	1657.00
1927-03-01	1675.00
1927-04-01	1388.00
1927-05-01	1417.00
1927-06-01	1333.00
1927-07-01	1418.00
1927-08-01	1427.00
1927-09-01	1468.00
1927-10-01	1523.00
1927-11-01	1497.00
1927-12-01	1536.00
1928-01-01	1457.00
1928-02-01	1380.00
1928-03-01	1446.00
1928-04-01	1200.00
1928-05-01	1281.00
1928-06-01	1252.00
1928-07-01	1259.00
1928-08-01	1300.00
1928-09-01	1314.00
1928-10-01	1436.00
1928-11-01	1411.00
1928-12-01	1405.00
1929-01-01	1528.00
1929-02-01	1445.00
1929-03-01	1531.00
1929-04-01	1370.00
1929-05-01	1344.00
1929-06-01	1257.00
1929-07-01	1393.00
1929-08-01	1383.00
1929-09-01	1380.00
1929-10-01	1508.00
1929-11-01	1528.00
1929-12-01	1454.00
1930-01-01	1514.00
1930-02-01	1371.00
1930-03-01	1404.00
1930-04-01	1249.00
1930-05-01	1320.00
1930-06-01	1125.00
1930-07-01	1277.00
1930-08-01	1214.00
1930-09-01	1279.00
1930-10-01	1344.00
1930-11-01	1280.00
1930-12-01	1427.00
1931-01-01	1378.00
1931-02-01	1190.00
1931-03-01	1255.00
1931-04-01	1156.00
1931-05-01	1115.00
1931-06-01	1149.00
1931-07-01	1189.00
1931-08-01	1116.00
1931-09-01	1182.00
1931-10-01	1266.00
1931-11-01	1168.00
1931-12-01	1240.00