Data from the International Tanker Owners Pollution Federation Limited give the cause of spillage for 459 oil tanker accidents resulting in spills of more than 700 tons of oil from 1970-2013.

a) Write a brief report interpreting what the displays show.
b) Is a pie chart an appropriate display for these data? Why or why not?
c) Were there more spills due to Collisions or to Groundings? Is it easier to tell that from the bar chart or the pie chart?