Staley Co. manufactures computer monitors. The following is a summary of its basic cost and revenue data: Per Unit Percent Sales price $525 100 Variable costs 300 57 Unit contribution margin $225 43 Assume that Staley Co. is currently selling 500 computer monitors per month and monthly fixed costs are $75,000. Staley Co.'s margin of safety ratio (MOS%) if 500 units are sold would be (round intermediate calculation up to nearest whole number of units):