OPINION — AG — THE EXEMPTION OF DOMESTIC INSURANCE COMPANIES FROM THE PAYMENT OF THE GROSS PREMIUM TAX REQUIRED OF FOREIGN INSURERS BY 36 O.S. 1971 624 [36-624], IS NOT UNCONSTITUTIONAL AS A DISCRIMINATORY TARIFF ON GOODS AND SERVICES BETWEEN STATES. CITE: ARTICLE XIX, SECTION 1, ARTICLE XIX, SECTION 2, 36 O.S. 1971 104 [36-104] (WILLIAM DON KISER)