Hyphens, En Dashes, Em Dashes

Q. Hello, No hyphen after a number and before the word “percent”; that’s the rule, per Chicago. But if part of a longer modifier, would the following be correct? Mike said, “A 15-to-20-percent-a-year increase in sales is what’s expected.” Thank you.

A. That’s tricky, but it doesn’t need to be. Just change “a-year” to “yearly” or “annual” (and edit out the redundant “what’s” while you’re at it). Now you have “a 15 to 20 percent annual increase in sales is expected.” Or you could use an en dash in place of “to”: “a 15–20 percent annual increase . . .” (see our hyphenation guide, under “number + percent”).