How old are the characters in IDW?

[neatoman]

So how old are the characters?

From youngest to oldest, my guess is:
Metalhead, 5-40 weeks.
Most of the animal characters (ignoring reincarnation), less than 6 years.
Angel, 16-20.
Casey, April, Karai and Lindsey, 18-23.
Bebop and Rocksteady, 25-38.
Hun and Brooklyn, 40-50.
Baxter and April's parents, 45-55.
Harold, 55-65.
Shredder, I forgot the century in which he was born, assuming it's the 1500's he's at least 500, give or take a century.
Kitsune, Rat King and Chi-You, Shredders age plus at least 200, probably way older.
Krang, ignoring that time might not pass the same way in Dimension X, millions of years old.

I don't even want to guess about the other alien characters, because that's too difficult.