Levi stock had returns of 21.70% (1 year ago), 2.40% (2 years ago), X (3 years ago), and -14.60% (4 years ago) in each of the past 4 years. Over the past 4 years, the geometric average annual return for Levi's stock was 2.85%. What was the arithmetic average annual return for the stock over the past 4 years?