In the percentages of amounts, sometimes it asks for 0% or 100%. These should be excluded
Also in percentages of amounts, can we consider any multiple of 5 (e.g. 5% or 35%), but with half the weighting of the other common ones? E.g. 25% should be twice as likely to come up as 5%, but 5% still has a chance of being a question.
Change name of second version to 'Percentage Change problems', and allow for percentage decreases as well as increases.
In the percentage changes, same as above: 0% and 100% should be excluded, multiples of 5% should be included.