Simulated distribution of the number of episodes per individual per year (top panel), and of the duration of episodes assumed for model scenarios 1 to 4 (bottom panel). The models scenarios are derived from a combination of the two different distributions for incidence and episode duration. Model scenario 1 combines low incidence and short duration, scenario 2 low incidence and long duration, scenario 3 high incidence and short duration, and scenario 4 high incidence and long duration. The black bars in top panel show the distribution assumed for the two scenarios with a low incidence, the white bars the distributions for the models with high incidence. Similarly, the black bars in bottom panel show the distribution of episode durations for the two models with a short mean episode duration, the white bars distribution for the models with long mean duration.