Until 9062.8 generations ago, the Y deme's population was fixed at 7493. From 9062.8 to 6173.0, it underwent a exponential reduction to 7148 individuals. Then, a exponential change brought the count to 1673 by 1451.256. Since then, from 1451.256 generations to the current day, the population has reduced from 1673 to 1492 at a exponential rate.
time_units: generations
demes:
  - name: Y
    start_time: .inf
    epochs:
      - start_size: 7493
        end_time: 9062.8
      - start_size: 7493
        end_size: 7148
        end_time: 6173.0
        size_function: exponential
      - start_size: 7148
        end_time: 1451.256
        end_size: 1673
        size_function: exponential
      - end_time: 0
        start_size: 1673
        end_size: 1492
        size_function: exponential