A taxable bond with a coupon rate of 4.00% has a market price of 99.12% of par. The bond matures in 9.00 years ans pays semi-annually. Assume an investor has a 27.00% marginal tax rate. The investor would prefer otherwise identical tax-exempt bond if it's yield to maturity was more than _____%

Answer format: Percentage Round to: 2 decimal places (Example: 9.24%, % sign required. Will accept decimal format rounded to 4 decimal places (ex: 0.0924))