Answer
They should change the starting point to 0.
Work Step by Step
The starting point of the bars is not 0, but more and this makes the frequencies look less. If they want them to look more they should change the starting point to 0.
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.