A savvy investor paid $6,500 for a 20 -year $10,000 mortgage bond that had a bond interest rate of 12% per year, payable quarterly. Three years after he purchased the bond, market interest rates went down, so the bond increased in value. If the investor sold the bond for $11,500 three years after he bought it, what rate of return did the investor make per quarter and per year (nominal)? The rate of return per quarter is The rate of return per year is