The population of deme B held at 7680 until 7962.0 generations back, when it decreased reaching 4883, which has been constant since then.
time_units: generations
demes:
  - name: B
    start_time: .inf
    epochs:
      - start_size: 7680
        end_time: 7962.0
      - start_size: 4883
        end_time: 0