Last year I was reading the entry in the Monster Manual on ogres and saw what it said about their age. I realized that I had not seen a table on the ages of the various humanoids like for the player character races, so I built my own chart in June, 2014 about the same time I made my name generator. You can get my humanoid age chart here.
Some of these creatures are quite long-lived, so it is reasonable for some of them to know quite a lot about regions they have lived for a few generations. How long has that ogre been under the bridge, etc.
This is not a table to roll on, but a chart showing the age breakdown based on how ages for the player character races ages are broken down in the Dungeon Master’s Guide. It has the ages for young adults on up and a basic age spread for each category. There may be other creatures that I missed that have ages listed, they can easily be added.