A scuba diver dove from the surface of the ocean to an elevation of −79 9
10
feet at a rate of −17.8 feet per minute. After spending 14.25 minutes at that elevation, the diver ascended to an elevation of −28
9
10
feet. The total time for the dive so far was 21
1
8
minutes. What was the rate of change in the diver's elevation during the ascent? Round your answer to the nearest hundredth.