109th century

In the 109th century, Kepzyr was supposed to be a thriving mid-level civilisation. After the intervention of Frank Reade Jr in Kepzyr's past, it became a wasteland. (PROSE: Frank Reade, Jr.'s Electric Time Canoe)

The Sixth Doctor estimated that Carmen was originally from the 108th or 109th century based on her time machine. (AUDIO: The Raincloud Man)