Until 9496.0 generations ago, the Y deme's population was fixed at 3935. From 9496.0 to 7887.195, it underwent a linear reduction to 2771 individuals. Then, a exponential increase brought the count to 8959 by 7819.38. Since then, from 7819.38 generations to the current day, the population has changed from 8959 to 3881 at a linear rate.
time_units: generations
demes:
  - name: Y
    start_time: .inf
    epochs:
      - start_size: 3935
        end_time: 9496.0
      - start_size: 3935
        end_size: 2771
        end_time: 7887.195
        size_function: linear
      - start_size: 2771
        end_time: 7819.38
        end_size: 8959
        size_function: exponential
      - end_time: 0
        start_size: 8959
        end_size: 3881
        size_function: linear