Namibia has free education for both Primary and secondary education levels. Grades 1–7 are primary level, grades 8–12 secondary. In 1998, there were 400,325 Namibian students in primary school and 115,237 students in secondary schools. The pupil-teacher ratio in 1999 was estimated at 32:1, with about 8% of the GDP being spent on education. Curriculum development, educational research, and professional development of teachers is centrally organised by the National Institute for Educational Development (NIED) in Okahandja.