The local ice cream shop sells single-scoop cones for $2.25 each. Its variable costs include the ice cream itself ($0.29 per scoop) and the cone ($0.04 per cone). The store manager plus one full-time and two part-time employees cost the business $3,480 per month in labor costs. Additional costs for rent and insurance come to $450 per month. What is the contribution margin per unit of a single-scoop cone? (Round answer to 2 decimal places, e.g. 15.25.)