Pro rata adjustment of entitlement amounts
If the total amount available for distribution in any fiscal year to metropolitan cities and urban counties under this section is insufficient to provide the amounts to which metropolitan cities and urban counties would be entitled under subsection (b), and funds are not otherwise appropriated to meet the deficiency, the Secretary shall meet the deficiency through a pro rata reduction of all amounts determined under subsection (b). If the total amount available for distribution in any fiscal year to metropolitan cities and urban counties under this section exceeds the amounts to which metropolitan cities and urban counties would be entitled under subsection (b), the Secretary shall distribute the excess through a pro rata increase of all amounts determined under subsection (b).