Amounts chargeable to and available from Federal sources for inpatient and outpatient services provided through Saint Elizabeths Hospital as authorized by
24 U.S.C.
191,
196,
211,
212,
222, 253, and
324;
31 U.S.C.
1535; and
42 U.S.C.
249 and
251 shall not exceed the estimated total cost of such services as computed using only the proportionate amount of the direct Federal subsidy appropriated under this heading.