Q parameter as a function of age for (from left to right): singles, pair subtypes B, C, Oa, and O, and groups. The percentages in the panel titles represent the fraction of each pair type relative to the total. The percentages in the boxes indicate the fraction of OCs with Q < 0.8. Marker sizes correspond to total mass. The horizontal dashed grey line marks Q = 0.8, while the vertical dashed grey lines indicate the median age of the pairs in the OC system (log(Age)[yr] = 8.1). In the left panel, we divide the plane into four quadrants, labelled I to IV.