Until 4971.84 generations ago, the population of deme Y was 6716. At that point, it decreased to 5782, where it has stayed up to now.
time_units: generations
demes:
  - name: Y
    start_time: .inf
    epochs:
      - start_size: 6716
        end_time: 4971.84
      - start_size: 5782
        end_time: 0