X deme's population was steady at 1758 before it changed to 7468 168.202 generations ago, maintaining that number to the present.
time_units: generations
demes:
  - name: X
    start_time: .inf
    epochs:
      - start_size: 1758
        end_time: 168.202
      - start_size: 7468
        end_time: 0