How to determine the pinout of this connector?
That is an IDT (insulation displacement technology) socket where the contacts actually press through the insulation to connect to the wires. What you want to know is that the wires are an interleave of the two rows shown in Keelan's pinout diagram.

From one end to the other, the wires correspond to the following pin numbers:

1, 6, 2, 7, 3, 8, 4, 9, 5.