The life cycle of elves (not a story)

Hey, what a perfect time for this question, since we're supposed to be all about the elves ... let's see if I can get an answer before the quiz changes:

At what age is an elf no longer considered a child? I know, the game books say that elves reach adulthood at 110, but does that mean that they're infants for 25 years, kids for another 25 and then teenagers for 50? Or do you think they grow from infancy to adolesence around the same rate as humans -- maybe a little slower -- and then spend the next 80 years as the mental equivalent of a human 15-year-old?

If the latter is the case, could you have a 30-year-old elf running around as an adventurer, since they'd be a teenager and not just a small child? Or would the elf really not be fit to leave the community until he reaches the century mark?

I'm playing around with a new story, so I need some feedback on this topic.

Rose of Jericho