On the streetfriends-website I just found this paragraph:
The cost of a public education (registration fees, uniforms, supplies, mandatory private lessons) prevents many families from sending their children to school. These children then spend extraordinary amounts of time unsupervised, either loitering or earning an income. An accurate census of the homeless or street population has yet to be carried out. Depending on the definition and according to the figures accepted by UNICEF, there are between 600 to 1,000 street children who have completely cut ties with their families and have made the streets their home and 10,000 street children who have kept ties with their family and return home either regularly or irregularly.