It is the purpose and intent of this subchapter to provide for a fair and equitable apportionment for the use of the facilities and services of the State Medical Center among the various counties of this state, and among all cities having in excess of ten thousand (10,000) population for the treatment of medical indigents, and to provide a method and procedure for charging such counties, and cities having over ten thousand (10,000) population, for services received by medical indigents at the medical center in excess of the allowed quotas.