The number of individuals in deme X remained at 2500 until 1432.0 generations ago, at which time it grew to a new stable size of 3258.
time_units: generations
demes:
  - name: X
    start_time: .inf
    epochs:
      - start_size: 2500
        end_time: 1432.0
      - start_size: 3258
        end_time: 0