A 3.5 percent treasury bond with semi-annual repayments (with par value of $100) with 16.5 years left to maturity is currently offered for sale at $102.3. What is the semi-annually compounded yield to maturity of the bond?

Note: Please express your result as a percentage and keep two digits after the decimal point (e.g., 12.34% or 1.23%) and assume an Actual/365 day count.