Until 3927.37 generations ago, the population of deme N was 3642. At that point, it changed to 9724, where it has stayed up to now.
time_units: generations
demes:
  - name: N
    start_time: .inf
    epochs:
      - start_size: 3642
        end_time: 3927.37
      - start_size: 9724
        end_time: 0