Deme T maintained a population of 8512 until there was a shift 6567.0745 generations ago that reduced its numbers to 5375, a figure that has remained the same since.
time_units: generations
demes:
  - name: T
    start_time: .inf
    epochs:
      - start_size: 8512
        end_time: 6567.0745
      - start_size: 5375
        end_time: 0