Left: current values of the normalized semimajor axis for close-in exoplanets as a function of the stellar age T_∗. Notice that bodies with are limited to young systems (T_∗ < 3 Gyr), while larger semimajor axes are found for all stellar ages. Right: original distribution in the diagram. Diagonal curves give limits to the orbital decay leading to disruption for two stellar ages: the continuous line show results for T_∗ = 1 Gyr, while the dashed line corresponds to T_∗ = 8 Gyr.