Sayyiduna Zayd bin Thabit (may Allah be pleased with him) says: For a bone-exposing wound (mudihah) there are five camels; for a fractured bone ten camels; for the head wound in which there are fragments of bone, fifteen camels; and for the extremely deep head wound one third of the blood money.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الديات / 16203