Under the Chicago Manual of Style, does "year over year" need hyphenation when preceding a noun?

Question

In the sentence, The company experienced strong year[-]over[-]year growth., how does the Chicago Manual of Style govern the hyphenation?

Part of me believes that it falls under the "phrases, adjectival" rules in § 7.89.2, but I'm not entirely sure. If it is governed by § 7.89.2 "phrases, adjectival" then my understanding is it would need to be hyphenated if preceding the noun like the example.

Answer 1

The Chicago Manual of Style, sixteenth edition (2010) addresses this issue (somewhat obliquely) in several separate entries. Here they are:

7.81 Compound modifiers before or after a noun. When compound modifiers (also called phrasal adjectives) such as open-mouthed or full-length precede a noun, hyphenation usually lends clarity. With the exception of proper nouns (such as United States) and compounds formed by an adverb ending in -ly (see 7.82) it is never incorrect to hyphenate adjectival compounds before noun. ...

and

7.83 Multiple hyphens. Multiple hyphens are usually appropriate for such phrases as an over-the-counter drug or a winner-take-all contest. ...

and

7.85 Hyphenation guide for compounds and words formed with prefixes. ...

[Category/specific term:] phrases, adjectival [Examples:] an over-the-counter drug | a matter-of-fact reply | an up-to-date solution | sold over the counter | her tone was matter of fact | hos equipment was up to date [Summary of rule:] Hyphenated before a noun; usually open after a noun.

These various guidelines indicate to me that Chicago would favor "year-over-year growth" but "growth year over year."