Average number of collisions per binary as a function of time (solid lines). The dotted lines refer to the expected number of collisions a single 1 M_⊙ star would have at 0.1 pc (black) and 0.3 pc (red). Because the binaries tend to migrate, the dashed lines show the same expectation as the dotted line, but where the distance is not fixed to the starting positions and instead follows the average outer orbit of the binaries. The pale dashed lines follow the apoapsis, while the non-transparent dashed lines follow the semi-major axis.