Doni observed the following returns on Bird-n-Nest Computer's stock over the past five years: 7 percent, -13 percent, 20 percent, 36 percent, and 11 percent. Suppose the average inflation rate over this period was 3.5 percent and the average T-bill rate over the period was 4.3 percent. What was the average real return on Bird-n-Nest's stock? (round 2 decimal)