Map of disc lifetimes as a function of stellar mass and X-ray luminosity, which is the main driver of internal photoevaporation, according to the surrogate model described in Sect. 4.2. External photoevaporation was set to its minimum value (F = 1 G₀). Other parameters were selected as M_G/M_⋆ = 0.1, ƒ_D/G = 0.0149, β = 0.9, P_in = 10 d, r₁ according to Eq. (9), α = 1 × 10⁻³, υ_frag = 2 m s⁻¹, ɛ = 1 × 10⁻³, and ζ = 1. The green dashed line represents the dependency of L_X on M_⋆ from Güdel et al. (2007) and the solid black line shows the location of a 3 Myr lifetime (a typical value). The results are discussed in Sect. 4.3.1.