Good Grooming Supplies takes inventory quarterly and bases inventory on selling price. Beginning inventory for the year was $91,000. Inventory at the end of the first quarter was $89,500; at the end of the second quarter, $74,120; at the end of the third quarter, $82,210; and at the end of the year, $79,170. Net sales for the year equal $249,600. Compute the inventory turnover at retail. How many units?