Up until 5800.499 generations ago, the count of T deme was 8259. Following that period, it changed to 4728, where it has persisted until now.
time_units: generations
demes:
  - name: T
    start_time: .inf
    epochs:
      - start_size: 8259
        end_time: 5800.499
      - start_size: 4728
        end_time: 0