Ten years ago, you borrowed $360,000 of a 30-year balloon mortgage loan (partially amortizing loan) with a 9% interest rate and a $100,000 balloon payment at the end of the term. You refinance this loan with a 20-year balloon mortgage with 8% interest rate and an $80,000 balloon payment. If the new balloon mortgage comes with an origination fee of $11,500, what is the rate of return (yield) of refinancing? (Assume that the borrower will not prepay the loan.)