Gas accretion rate as a function of dust (black circles) and gas (red squares) disc mass for protoplanetary discs of the stellar cluster. The dashed black lines show power-law fits of the accretion rate as a function of the gas disc mass (). The discs are given a random individual age of between 0.0 and 1.0 Myr to mimic a spread in formation times. Panels from a to d: protoplanetary discs at the cluster ages of 1.0, 1.5, 2.0, and 3.0 Myr. For the first 1 Myr the dust is coupled well to the gas inmost discs, and dust disc masses evolve in a very similar way to the gas disc mass. Some of the lowest mass discs have reached the dust drift turn-over at this point. Beyond this time more and more of the dust discs reach the dust turn-over and begin to drain rapidly. At 1.5 Myr the lower mass discs have reached the turn-over point, as can be seen in the flattening of the low-mass end of the dust discs in panel b. At 2 Myr only the most massive dust discs are yet to reach the turn-over and at 3 Myr nearly all discs are drained of dust. Only 4 out of 100 discs still have a dust mass greater than 1 M_⊕, although two of these have a mass of more than 100 Earth masses.