W deme's population was steady at 6306 before it increased to 7601 6013.0 generations ago, maintaining that number to the present.
time_units: generations
demes:
  - name: W
    start_time: .inf
    epochs:
      - start_size: 6306
        end_time: 6013.0
      - start_size: 7601
        end_time: 0