Ibbotson U.S. Intermediate-Term Government Bond Index is now calculated from Wall Street Journal prices. One-bond portfolios are used to construct the intermediate-term index. The bond chosen each year is the shortest noncallable bond with a maturity of not less than five years, and it is "held" for the calendar year. Total returns are calculated as the change in the flat or "and-interest" price. The flat price is the average of the bid and ask prices plus the accrued coupon.