In July 1970, Macias created a single-party state and by May 1971, key portions of the constitution were abrogated. In 1972 Macias took complete control of the government and assumed the title of President for Life. The Macias regime was characterized by human rights abuses, totalitarianism and the abandonment of all government functions except internal security, which was accomplished by terror; this led to the death or exile of up to one-third of the country's population. Due to pilferage, ignorance, and neglect, the country's infrastructure—electrical, water, road, transportation, and health—fell into ruin. The private and public sectors of the economy were devastated. Nigerian contract labourers on Bioko, estimated to have been 60,000, left en masse in early 1976. The economy collapsed, and skilled citizens and foreigners left.