Deme W maintained a population of 5960 until there was a shift 7138.322 generations ago that changed its numbers to 5719, a figure that has remained the same since.
time_units: generations
demes:
  - name: W
    start_time: .inf
    epochs:
      - start_size: 5960
        end_time: 7138.322
      - start_size: 5719
        end_time: 0