Initially, the population size of deme U stood at 7674, but this changed 7919.0 generations ago when it changed to 5371, and it has been stable at that size up to today.
time_units: generations
demes:
  - name: U
    start_time: .inf
    epochs:
      - start_size: 7674
        end_time: 7919.0
      - start_size: 5371
        end_time: 0