Theoretical determination of energies, wavelengths, and transition rates for the Y30+–Y36+ spectra of fusion interest

•Excitation energies, transition wavelengths, and transition probabilities for the L-shell charge states of yttrium ions are reported.•Comparison with the recent EBIT spectra of the NIST allowed us to perform consistency checks and estimate the uncertainty of the data.•The present data particularly important for fusion research.