Numbers
Q. Section 9.18 (16th ed.) says always use numerals for percentages. Fine. But I’m editing a book of fiction. One paragraph of narration uses a percentage, and then the next paragraph uses a percentage in dialogue. What to do? Here’s an example: Steven was told that 78 percent of the neighborhood had been spared. “Yeah, but what are we to do about the remaining twenty-two percent?” he groaned.
A. You can leave it as you have it, or, if that bothers you, you can spell out the numerals for the sake of “regional consistency.”
Chicago Style Q&A: New Questions and Answers

