Some of those numbers are a bit deceptive. In the shipping industry, a container port's activity is measured by container lifts per year. But for a lot of these Asian ports (including Singapore) the container lifts aren't an accurate measure of cargo origin or destination. Many of these ports have a lot of
transshipment lifts, which means a container is lifted off one ship and loaded on another one without ever moving through a terminal gate.
I think Rotterdam would be much closer to the top of this list if the container lift count only includes cargo originations and destinations at the port.