Histograms (in red) of the ages, masses, radius, and rms velocities and scatter plots of the square root (to use the same scale as the histograms) of the ratio of kinetic and gravitational energies versus the same quantities (blue dots) of the 339 clusters identified in the six simulation snapshots used in this work. The black dashed line marks the value of E_k = E_g, showing that 5% of the clusters (17 of them) are gravitationally bound.