Originally, deme U had a population size of 299, which increased to 7096 around 9790.75 generations ago and has not changed since.
time_units: generations
demes:
  - name: U
    start_time: .inf
    epochs:
      - start_size: 299
        end_time: 9790.75
      - start_size: 7096
        end_time: 0