Until a shift occurred 2468.63 generations ago, deme X's population was consistently 9433. Since then, it changed to 4331, a number that has remained unchanged to the current time.
time_units: generations
demes:
  - name: X
    start_time: .inf
    epochs:
      - start_size: 9433
        end_time: 2468.63
      - start_size: 4331
        end_time: 0