Primary education is free in Nicaragua. A system of private schools exists, many of which are religiously affiliated and often have more robust English programs. As of 1979, the educational system was one of the poorest in Latin America. One of the first acts of the newly elected Sandinista government in 1980 was an extensive and successful literacy campaign, using secondary school students, university students and teachers as volunteer teachers: it reduced the overall illiteracy rate from 50.3% to 12.9% within only five months. This was one of a number of large-scale programs which received international recognition for their gains in literacy, health care, education, childcare, unions, and land reform. The Sandinistas also added a leftist ideological content to the curriculum, which was removed after 1990. In September 1980, UNESCO awarded Nicaragua the Soviet Union sponsored Nadezhda Krupskaya award for the literacy campaign.