Deme P maintained a population of 1562 until there was a shift 4473.7212 generations ago that increased its numbers to 7571, a figure that has remained the same since.
time_units: generations
demes:
  - name: P
    start_time: .inf
    epochs:
      - start_size: 1562
        end_time: 4473.7212
      - start_size: 7571
        end_time: 0