It may be age-d to you, but every month I print out an Aged Debtors List, not an Age-d Debtors List.

And in many parts of England it is customary to use the singular form of a noun after a numeral - forty pound, fiteen mile, four foot etc - the number tells you it's plural anyway, so pluralising the noun is redundant. (Doesn't Russian use the genitive singular after numbers bigger than 4?)

WassaiL! V