Up until 4281.67 generations ago, the count of R deme was 8298. Following that period, it changed to 7058, where it has persisted until now.
time_units: generations
demes:
  - name: R
    start_time: .inf
    epochs:
      - start_size: 8298
        end_time: 4281.67
      - start_size: 7058
        end_time: 0