In 1981 a team of researchers from the Maison de l'Orient et de la Méditerranée, including Jacques Cauvin and Oliver Aurenche divided Near East neolithic chronology into ten periods (0 to 9) based on social, economic and cultural characteristics. In 2002 Danielle Stordeur and Frédéric Abbès advanced this system with a division into five periods. Natufian (1) between 12,000 and 10,200 BC, Khiamian (2) between 10,200-8,800 BC, PPNA: Sultanian (Jericho), Mureybetian, early PPNB (PPNB ancien) (3) between 8,800-7,600 BC, middle PPNB (PPNB moyen) 7,600-6,900 BC, late PPNB (PPNB récent) (4) between 7,500 and 7,000 BC and a PPNB (sometimes called PPNC) transitional stage (PPNB final) (5) where Halaf and dark faced burnished ware begin to emerge between 6,900-6,400 BC. They also advanced the idea of a transitional stage between the PPNA and PPNB between 8,800 and 8,600 BC at sites like Jerf el Ahmar and Tell Aswad.