In allocating funds appropriated pursuant to the authorization contained in subsection (a) of this section among the Bureau, Office, tribal governments and Courts of Indian Offenses, the Secretary shall take such actions as may be necessary to ensure that such allocation is carried out in a manner that is fair and equitable to all tribal governments and is proportionate to base support funding under section
3613 of this title received by the Bureau, Office, tribal governments, and Courts of Indian Offenses.