For much of the period between 1950 and 1973, the Venezuelan economy was characterized by its stability and sustained strength, factors that contributed decisively to being able to maintain a fixed exchange rate without major inconveniences. In the period of Carlos Andrés Pérez (1974–1979, his first time as president), as a result of the Arab-Israeli war (the Yom Kippur War), the average price of a barrel of oil went from 3.71 to 10.53 dollars and continued to rise to exceed 29 dollars in 1981. The income of the public sector went from 18,960 million bolivars in 1973 to 45.564 million in 1974. The economic bonanza also had the characteristics of an economic bubble, but Venezuelans remember the "Ta barato, dame dos". The increased inflow of funds to savings and loan entities and mortgage banks allowed an increase in the mortgage loan portfolio, which also tripled. In general, Venezuela was a prosperous country in the governments of Rómulo Betancourt (1945 – ; 1959–1964), Rafael Caldera (1969–1974; 1994 – ) and Carlos Andrés Pérez (1974–1979; 1989 – ). In 1975 the iron industry was nationalized and the following year the oil industry, creating Petróleos de Venezuela, S.A. (PDVSA). Both Caldera and Pérez partially broke with the Betancourt Doctrine.