During the period ca. 1940–1960, Mexico experienced sustained economic growth, the so-called Mexican Miracle, which saw increased urbanization and industrialization. The idea that education was a determinant of economic development took hold and the government of President Adolfo López Mateos, who appointed Torres Bodet Minister of Education. Torres Bodet made a comprehensive assessment of Mexican education, which led to the Eleven-Year Plan for Education, attempting to make a commitment that forced the next president to continue implementation. The assessment of Mexican primary-level schools showed that 50% of Mexican children, or 3 million, had access to primary education. Of those, fewer than 25% finished 4th grade. Only about 1,000 of those primary school students would succeed in pursuing a profession. A basic finding was that only 50% of Mexicans could read or write. López Mateos sought reforms to remedy the situation, including training 27,000 more teachers and building more schools. He also created a program to provide free textbooks to students and made their use obligatory in schools.