How old is each member of organisation XIII

At first only Roxas' age was known, but then in an interview Nomura Tetsuya revealed some of the member's ages.
Xemnas is in his late 20s or early 30s.
Roxas is 14 or 15.
Axel is in his early 20s, possible 21-24.
Demyx is possibly 17.
Zexion is also possibly 17 or 16.
Larxene is most likely in her early or mid 20s.
Saix is either in his mid or late 20s.

I forgot which members ages are confirmed or an assumption. But these ages are most likely possible.