The Ibbotson U.S. Intermediate-Term Government Bond Index is an unweighted index which measures the performance of five-year maturity U.S. Treasury Bonds. Each year a one-bond portfolio containing the shortest non-callable bond having a maturity of not less than five years is constructed. Bonds with impaired negotiability or special redemption privileges are omitted, as are partially or fully tax-exempt bonds starting in 1943. To measure holding period returns for the one-bond portfolio, the bond is priced (with accrued coupons) over the holding period and total returns are calculated.