Completeness-corrected age function of OCs in this work (black points) compared against various age functions in the literature. Dashed lines show broken power law fits while dotted lines show Schechter function fits. Literature age functions are normalised to ages below 0.2 Gyr for easier visualisation of differences in shape of the upper end of the distributions. The blue lines show fits from Krumholz et al. (2019), the orange lines from Anders et al. (2021), and the red lines are fits from this work. Poisson uncertainties on the data are indicated by the error bars. Schechter function fits from Krumholz et al. (2019) and Anders et al. (2021) have characteristic ages scaled by a factor log₁₀e to correct for an error in their Schechter function fitting codes.