Month	Thousands Of Hours
1920-01-01	1389.00
1920-02-01	1245.00
1920-03-01	1388.00
1920-04-01	1320.00
1920-05-01	1390.00
1920-06-01	1421.00
1920-07-01	1525.00
1920-08-01	1505.00
1920-09-01	1453.00
1920-10-01	1356.00
1920-11-01	1368.00
1920-12-01	1418.00
1921-01-01	1390.00
1921-02-01	1273.00
1921-03-01	1393.00
1921-04-01	1146.00
1921-05-01	847.000
1921-06-01	859.000
1921-07-01	1341.00
1921-08-01	1535.00
1921-09-01	1445.00
1921-10-01	1403.00
1921-11-01	1383.00
1921-12-01	1414.00
1922-01-01	1389.00
1922-02-01	1271.00
1922-03-01	1420.00
1922-04-01	1314.00
1922-05-01	1442.00
1922-06-01	1460.00
1922-07-01	1535.00
1922-08-01	1597.00
1922-09-01	1514.00
1922-10-01	1437.00
1922-11-01	1423.00
1922-12-01	1402.00
1923-01-01	1466.00
1923-02-01	1310.00
1923-03-01	1444.00
1923-04-01	1393.00
1923-05-01	1505.00
1923-06-01	1497.00
1923-07-01	1626.00
1923-08-01	1713.00
1923-09-01	1567.00
1923-10-01	1550.00
1923-11-01	1497.00
1923-12-01	1482.00
1924-01-01	1314.00
1924-02-01	1430.00
1924-03-01	1496.00
1924-04-01	1480.00
1924-05-01	1568.00
1924-06-01	1544.00
1924-07-01	1714.00
1924-08-01	1724.00
1924-09-01	1623.00
1924-10-01	1568.00
1924-11-01	1451.00
1924-12-01	1524.00
1925-01-01	1555.00
1925-02-01	1379.00
1925-03-01	1500.00
1925-04-01	1483.00
1925-05-01	1531.00
1925-06-01	1607.00
1925-07-01	1742.00
1925-08-01	1759.00
1925-09-01	1640.00
1925-10-01	1585.00
1925-11-01	1478.00
1925-12-01	1560.00
1926-01-01	1526.00
1926-02-01	1393.00
1926-03-01	1557.00
1926-04-01	1499.00
1926-05-01	751.000
1926-06-01	1038.00
1926-07-01	1404.00
1926-08-01	1619.00
1926-09-01	1557.00
1926-10-01	1528.00
1926-11-01	1478.00
1926-12-01	1522.00
1927-01-01	1515.00
1927-02-01	1388.00
1927-03-01	1555.00
1927-04-01	1507.00
1927-05-01	1538.00
1927-06-01	1625.00
1927-07-01	1737.00
1927-08-01	1789.00
1927-09-01	1658.00
1927-10-01	1567.00
1927-11-01	1523.00
1927-12-01	1599.00
1928-01-01	1544.00
1928-02-01	1466.00
1928-03-01	1589.00
1928-04-01	1495.00
1928-05-01	1640.00
1928-06-01	1642.00
1928-07-01	1752.00
1928-08-01	1839.00
1928-09-01	1650.00
1928-10-01	1616.00
1928-11-01	1540.00
1928-12-01	1548.00
1929-01-01	1599.00
1929-02-01	1432.00
1929-03-01	1556.00
1929-04-01	1571.00
1929-05-01	1667.00
1929-06-01	1619.00
1929-07-01	1817.00
1929-08-01	1875.00
1929-09-01	1662.00
1929-10-01	1640.00
1929-11-01	1567.00
1929-12-01	1559.00
1930-01-01	1621.00
1930-02-01	1447.00
1930-03-01	1574.00
1930-04-01	1568.00
1930-05-01	1639.00
1930-06-01	1654.00
1930-07-01	1813.00
1930-08-01	1828.00
1930-09-01	1676.00
1930-10-01	1611.00
1930-11-01	1498.00
1930-12-01	1571.00
1931-01-01	1594.00
1931-02-01	1412.00
1931-03-01	1542.00
1931-04-01	1532.00
1931-05-01	1602.00
1931-06-01	1618.00
1931-07-01	1752.00
1931-08-01	1783.00
1931-09-01	1621.00
1931-10-01	1586.00
1931-11-01	1471.00
1931-12-01	1544.00