The ship waiting indicator is calculated as the average waiting hours per ship, by type of commodity. Average waiting time is also sometimes compared to average time at berth to produce the ship-waiting rate. The various elements contributing to the waiting time should be analyzed to allow the port authority to precisely identify cases whereby it was the result of non-availability of port facilities or equipment. Discuss the Port of Durban's performance in a time-series spanning 2012 to 2019.

For this one I need annual figures. If you cannot find annual figures for the port of your choosing, then gather data and determine the annual average for each port (for the latter you will have to show your workings)