Come to think of it, why aren't zetta and yotta the other way round? That way you'd at least get (e)x y z at the end, which would make some kind of sense.
Cause zetta and yotta are greek letters and that is the order they come in the greek alphabet?
At least that is what my greek teacher told me.
http://www.ibiblio.org/koine/greek/lessons/alphabet.html
Alex
Egho Then Mila Ellinika
(Which means "I don't speak greek" in greek)