Until a shift occurred 3197.232 generations ago, deme P's population was consistently 6983. Since then, it decreased to 5287, a number that has remained unchanged to the current time.
time_units: generations
demes:
  - name: P
    start_time: .inf
    epochs:
      - start_size: 6983
        end_time: 3197.232
      - start_size: 5287
        end_time: 0