Deme Z maintained a population of 4924 until there was a shift 2294.46 generations ago that grew its numbers to 8491, a figure that has remained the same since.
time_units: generations
demes:
  - name: Z
    start_time: .inf
    epochs:
      - start_size: 4924
        end_time: 2294.46
      - start_size: 8491
        end_time: 0