The population of deme K held at 8042 until 613.918 generations back, when it changed reaching 8045, which has been constant since then.
time_units: generations
demes:
  - name: K
    start_time: .inf
    epochs:
      - start_size: 8042
        end_time: 613.918
      - start_size: 8045
        end_time: 0