One of the main factors contributing to this relatively low literacy rate is usefulness of education and availability of schools in vicinity in rural areas. There is a shortage of classrooms to accommodate all the students in 2006–2007. In addition, there is no proper sanitation in most schools. The study of 188 government-run primary schools in central and northern India revealed that 59% of the schools had no drinking water facility and 89% no toilets. In 600,000 villages and multiplying urban slum habitats, 'free and compulsory education' is the basic literacy instruction dispensed by barely qualified 'para teachers'. The average pupil teacher ratio for all India is 42:1, implying a teacher shortage. Such inadequacies resulted in a non-standardized school system where literacy rates may differ. Furthermore, the expenditure allocated to education was never above 4.3% of the GDP from 1951 to 2002 despite the target of 6% by the Kothari Commission. This further complicates the literacy problem in India.