J deme's population was steady at 7081 before it decreased to 362 4889.1046 generations ago, maintaining that number to the present.
time_units: generations
demes:
  - name: J
    start_time: .inf
    epochs:
      - start_size: 7081
        end_time: 4889.1046
      - start_size: 362
        end_time: 0