A further impetus to economic liberalization came from the September 1953 signing of a mutual defense agreement, the Pact of Madrid, between the United States and Spain. In return for permitting the establishment of United States military bases on Spanish soil, the administration of President Dwight D. Eisenhower administration provided substantial economic aid to the Franco regime. More than US$1 billion in economic assistance flowed into Spain during the remainder of the decade as a result of the agreement. Between 1953 and 1958, Spain's gross national product (GNP) rose by about 5% per annum.