I NEED IT ASAP PLEASE

Twinde incorporation had the following returns over the past five years: 5 percent, 10 percent, 12 percent, 13 percent, -5 percent. If the average t-bill rate was 5 percent and the average inflation rate over this time period was 2 percent, what was the average nominal risk premium? (Write your answer in terms of %. If your answer is 15% write 15)