Deme U had an initial size of 9055 until 828.38 generations ago. At that time, its population size changed to 4746, and has remained there till current time.
time_units: generations
demes:
  - name: U
    start_time: .inf
    epochs:
      - start_size: 9055
        end_time: 828.38
      - start_size: 4746
        end_time: 0