From publisher blurb:
This game aid presents a handy alternative for awarding development points during character generation in the MYTHRAS gaming system. Older characters receive more bonus points in the rules as written, but the progression is not smooth, and does not address certain questions. In a more finely grained system, exactly how many bonus points does a character receive at any particular age? Suppose that a character takes a long break from adventuring and then returns; how many bonus points should be awarded for the intervening span of "regular life"? How many bonus points would an unusually old character receive, beyond the tabulated ages in the rules? This supplement offers a systematic, analytical approach to answering those questions.
To be clear, Skill Points by Age has been crafted specifically for the MYTHRAS gaming system. Any compatibility with other systems is fortuitous. You may find some inspiration here, though.