Until 3677.7478 generations ago, the population of deme Z was 9577. At that point, it changed to 8797, where it has stayed up to now.
time_units: generations
demes:
  - name: Z
    start_time: .inf
    epochs:
      - start_size: 9577
        end_time: 3677.7478
      - start_size: 8797
        end_time: 0