Coupon payments of Treasury bonds are subject to 32% tax rate but municipal bonds are tax exempt. You are considering the following two bonds:

1. 10-year Treasury bond with coupon rate 5% and face value $5,000 priced at $5,200 today.
2. 10-year municipal bond with coupon rate 4% and face value %10,000 priced at $9,800 today.

What is the after-tax yield to maturity (in %) of the municipal bond? Round your answer to at least 2 decimal places.