What Bart 10 years old and Lisa 8 years old?

I think I saw or worked out bart was born in '83 same as me or around that time poss '84 so Bart would be 27ish and Lisa would be 25ish or 28ish and26ish. Although as everyone else says they are cartoons and therefore never age like Dennis The Menace from Beano he's been 10 or thereabouts for over 50 years