Darwin Company sells glass vases at a wholesale price of $ 5.00 per unit. The variable cost to manufacture is $ 2.00 per unit. The monthly fixed costs are $ 8 comma 000. Its current sales are 25 comma 000 units per month. If the company wants to increase its operating income by 30%, how many additional units must it sell? (Round any intermediate calculations to two decimal places and your final answer to the nearest whole number.)