Up until 3581.0 generations ago, the count of S deme was 7819. Following that period, it changed to 8822, where it has persisted until now.
time_units: generations
demes:
  - name: S
    start_time: .inf
    epochs:
      - start_size: 7819
        end_time: 3581.0
      - start_size: 8822
        end_time: 0