An initial deposit of $10000 is made into an account now, and a second deposit of $18000 is made into the same account after 15 years. During the first 10 years, the account earns interest quoted at a nominal quarterly discount rate of d%. After 10 years have passed, any money in the account earns a nominal semi-annual interest rate of 4.6%. At the end of 30 years, the total value of the account will be $86440. What is the value of d (to the nearest 0.1%)?