The deme of Y kept its population at 7225 until 9504.0 generations ago, when a linear reduction ensued until 8082.07, to size 646. Subsequently, a linear change changed the numbers to 3376 individuals by 3459.5. Starting from 3459.5, the population has seen a decrease from 3376 to 3359 at a linear pace, continuing to this day.
time_units: generations
demes:
  - name: Y
    start_time: .inf
    epochs:
      - start_size: 7225
        end_time: 9504.0
      - start_size: 7225
        end_size: 646
        end_time: 8082.07
        size_function: linear
      - start_size: 646
        end_time: 3459.5
        end_size: 3376
        size_function: linear
      - end_time: 0
        start_size: 3376
        end_size: 3359
        size_function: linear