We study the photoluminescence and photoluminescence excitation intensities of single-walled carbon nanotubes. To derive the chirality fractions of semiconducting tubes from these optical methods requires a thorough analysis of the experimental parameters and the lifetimes of the excitonic states. We obtain the intensity distribution from the product of the widths of the first and second excitonic transition and the intensity of the absorption of the second excited state. Compared with previous analysis protocols our intensity distribution points towards a chirality abundance which is (i) narrower in diameter, (ii) centred at smaller diameters and (iii) more strongly dominated by armchair-like tubes. We present a recipe for the fit of luminescence data.