Until a shift occurred 6120.2 generations ago, deme X's population was consistently 2762. Since then, it decreased to 301, a number that has remained unchanged to the current time.
time_units: generations
demes:
  - name: X
    start_time: .inf
    epochs:
      - start_size: 2762
        end_time: 6120.2
      - start_size: 301
        end_time: 0