The fund will invest at least 90% of its net assets (including, for this purpose, any borrowings for investment purposes) in securities included in the index. The index includes all publicly-issued U.S. Treasury securities that have a remaining maturity of greater than or equal to three years and less than ten years, are rated investment grade, and have $300 million or more of outstanding face value. The securities in the index must be denominated in U.S. dollars and must be fixed-rate and non-convertible.