A scuba diver dove from the surface of the ocean to an elevation of -59 9/10 feet at a rate of -12.6 feet per minute. After spending 10.5 minutes at that elevation, the diver ascended to an elevation of -8 9/10 feet. The total time for the dive so far was 17 1/8 minutes. What was the rate of change in the diver's elevation during the ascent? Round your answer to the nearest hundredth. The rate of change of the diver's elevation was ft/min.