Most well-known style guides dictate that numbers should always be spelled out at the beginning of a sentence (Forty-seven percent of people...), even to the point of recommending rewriting to avoid spelling out awkwardly large numbers (In all, 5,260 people...).
I have a bulleted list of percentages in which I would really like to start all of the list items with numerals:
- 12 percent of messages...
- 50 percent of messages...
- 19 percent of messages...
- 4 percent of messages...
Spelling all the numbers out would significantly harm readability. Rewriting to put the numbers later would also harm readability, in addition to appearing contrived. I've checked my Chicago Manual of Style, but it doesn't seem to address this particular situation, or at least I haven't been able to find it.
Are there any commonly accepted sources that offer guidance on this point, or is it just too rare to have come up?