Musannaf Ibn Abi Shaybah

Hazrat Awza'i states that the usual practice of the reciters during Tarawih was that they would recite the Holy Qur'an in sequence; each subsequent reciter would continue from the point where the previous reciter had left off. Then, when the era of Hazrat Umar bin Abdul Aziz came, he said that every reciter may recite from wherever he wishes.