Private schools in Delhi—which use either English or Hindi as the language of instruction—are affiliated to one of three administering bodies, the Council for the Indian School Certificate Examinations (CISCE), the Central Board for Secondary Education (CBSE) or the National Institute of Open Schooling (NIOS). In 2004–05, approximately 1,529,000 students were enrolled in primary schools, 822,000 in middle schools and 669,000 in secondary schools across Delhi. Female students represented 49% of the total enrolment. The same year, the Delhi government spent between 1.58% and 1.95% of its gross state domestic product on education.