Logan, Inc., had 9,000 units of work in process in Department M on March 1 that were 50 percent complete as to conversion costs. Materials are introduced at the beginning of the process. During March, 18,000 units were started, 20,000 units were completed, and there were 1,000 units of normal losses. Logan had 6,000 units of work in process at March 31 that were 60 percent complete as to conversion costs. Under Logan's cost accounting system, lost units reduce the number of units over which total cost can be spread. Using the average cost method, what were the equivalent units for March for conversion costs?