The Cool-Tech Company produces various types of fans. In May, the company produced 1,728 window fans at a standard price of $40.00. The company has 12 direct labor employees whose compensation (including wages and fringe benefits) amounts to $21.00 per hour. During May, window fans were produced on 9 working days (of 8 hours each), and other products were produced on other days. Determine the labor productivity of the window fans.