Distribution of the confirmed exoplanets of the S₁ sample in the log P – log R_p diagram for different ranges of the insulation flux. The upper left panel shows the 586 planets that receive ≤50 F_⊕, the upper right panel shows the 364 planets that receive between 50 F_⊕ and 200 F_⊕, the lower left panel depicts the 238 planets that receive between 200 F_⊕ and 550 F_⊕, and the lower right panel illustrates the 339 planets with F > 550 F_⊕.