Until 2230.8242 generations ago, the population of deme A was 8813. At that point, it changed to 5037, where it has stayed up to now.
time_units: generations
demes:
  - name: A
    start_time: .inf
    epochs:
      - start_size: 8813
        end_time: 2230.8242
      - start_size: 5037
        end_time: 0