For deme D, the population count was 2610 until a change 8501.0441 generations ago, where it changed to 6152, remaining steady thereafter.
time_units: generations
demes:
  - name: D
    start_time: .inf
    epochs:
      - start_size: 2610
        end_time: 8501.0441
      - start_size: 6152
        end_time: 0