the following purposes: (1) Return on investment Such amounts as are pledged by a participating tribe pursuant to section 904(10) for return on the investment made by the investor partner or other investors may be used by the Secretary to ensure such full return on investment. (2) Administrative expenses The Secretary may provide to a participating tribe, upon the request of a tribe, not more than 10 percent of any annual allocation made under title III for the tribe during such period for administrative costs of the tribe in completing the processes to carry out sections 903 and 904. (3) Housing infrastructure costs A participating tribe may use such amounts for housing infrastructure costs associated with providing affordable housing for the tribe under the final plan. (4) Maintenance