Number density of the visible γ-ray pulsars obtained for each model as a function of characteristic age and energy flux times the square of the pulsar distance. These parameters can all be measured from the observations. The linear grey scale saturates at 1 star/bin for the polar cap and 2.5 star/bin for the other models. The pink contours outline the region where simulated radio-loud γ-ray pulsars are found (at 20% of the maximum density). The pink and green lines show the data for the radio-loud and radio-quiet LAT pulsars, respectively.