The Finishing Department had 6,500 incomplete units in its beginning Work-in-Process Inventory which were 100% complete as to materials and 30% complete as to conversion costs. 19,500 units were received from the previous department. The ending Work-in-Process Inventory consisted of 2,550 units which were 50% complete as to materials and 30% complete as to conversion costs. The Finishing Department uses first-in, first-out (FIFO) process costing. What are the equivalent units of production for materials during the period?