Detected fractions in the HE (left panels) and VHE (right panels) surveys. Each panel contains four curves corresponding to P_inj = 10³³,10³⁴,10³⁵,10³⁶ erg/s (dark to light blue sequence in each panel). The detection fraction increases when going from small P_inj (darker blue) to high P_inj (lighter blue) until the detected fraction saturates at the value given by the observable fraction (Table 2).