As mortgage interest rates hit their lowest level in 16 months, refinance applications soared 8% as borrowers raced to cash in on savings. According to the Mortgage Bankers Association, that jump in refinance requests pushed overall mortgage applications up 2.4% in the latest week. Home purchase applications fell 2% however. During the same time, the average rate on a 30-year fixed rate mortgage dropped to 4.33%, down from 4.4% the previous week.