The population of deme C held at 973 until 5026.14 generations back, when it changed reaching 2117, which has been constant since then.
time_units: generations
demes:
  - name: C
    start_time: .inf
    epochs:
      - start_size: 973
        end_time: 5026.14
      - start_size: 2117
        end_time: 0