For deme O, the population count was 632 until a change 9923.0 generations ago, where it grew to 5227, remaining steady thereafter.
time_units: generations
demes:
  - name: O
    start_time: .inf
    epochs:
      - start_size: 632
        end_time: 9923.0
      - start_size: 5227
        end_time: 0