Schuman Corporation produces microwave units. The following per-unit cost information is available: direct materials $38; direct labour $25; variable manufacturing overhead $20; fixed manufacturing overhead $42; variable selling and administrative expenses $16; and fixed selling and administrative expenses $30. Its desired ROI per unit is $30.96. Calculate the markup percentage using variable-cost pricing. (Round answer to 2 decimal places, e.g. 15.25%.