Wells Fargo issues a CMBS. The mortgage pool consist of interest only loans, with a total loan amount of $15 million. Assume the mortgage rate in the pool is 11%, the mortgages are annually compounded and the loan maturity is 4 years. The are three trenches in the CMBS: 1.Tranche A, with an amount of $10 million at 8% coupon rate, 2. Tranche B, #3 million at 10% coupon rate, 3. The residual tranche, with $2 million. The maturity of the MBS is 4 years. Suppose some loans are in default, so only 70% of the original loan amount can be recovered at the end of 4th year. However, the mortgage pool can still generate the same amount of cash flow available in year 4 as those in the first 3 years. What is the investor return for the Tranche B for the 4 year period?