Originally, deme Z had a population size of 8764, which reduced to 3482 around 2473.6 generations ago and has not changed since.
time_units: generations
demes:
  - name: Z
    start_time: .inf
    epochs:
      - start_size: 8764
        end_time: 2473.6
      - start_size: 3482
        end_time: 0