The separations of the various components of 44 trapezia as a function of time are studied, taking advantage of many new, high precision observations for these objects. A previous study revealed that some systems have components moving with velocities larger than the escape velocity (Allen et al.1974). The present work updates our previous study, extending the observations by about 30 years, and thus allowing an improved determination of the relative transverse motions of the components. The analysis of the new data confirms the conclusions we reached in our previous work: most of the trapezia show the internal motions expected for bound, virialized small clusters, but a few have escaping components. The available observational material lends support to the concept that trapezia are unstable systems with lifetimes of the order of a few million years.
