Is either of these approaches to hyphenation currently more popular than the other one is when it comes to printed publications?
- The drug is most promising for three-to-fifteen-year-old children.
- The drug is most promising for three- to fifteen-year-old children.
I understand that the currently popular instruction on punctuating compound modifiers demands that one place a hyphen between each individual word in a modifier that's made up of several words (as in example #1), but I am pretty sure I have also seen such modifiers punctuated like the one given in example #2 a few times as well.
Sadly, searches on the internet and style guides such as Practical English Usage do not discuss this specific construction where we're talking about a range of numbers.