Initially, the population size of deme Z stood at 2739, but this changed 9175.0 generations ago when it changed to 5036, and it has been stable at that size up to today.
time_units: generations
demes:
  - name: Z
    start_time: .inf
    epochs:
      - start_size: 2739
        end_time: 9175.0
      - start_size: 5036
        end_time: 0