Frequency of stars hosting JL planets (corrected for completeness) in individual associations as a function of age. Blue dots are associations with a total mass <100 M_⊙ (Gratton et al. 2024); orange squares are associations with a total mass >100 M_⊙ (Gratton et al. 2024); red circles are the open clusters discussed in this paper. We corrected the observed frequency in Hyades for the higher than solar metallicity of the cluster. The open square represents the frequency of stars hosting JL planets from the RV surveys (adapted from Fernandes et al. 2019, see Appendix A). We arbitrarily assumed an age of 4 Gyr as typical for the stars in these surveys.