Miffy is about right - I'd maybe adjust a % or two but that's pretty much spot on.

I would advise a relative newcomer to aim for stats in the tight band. Under 14% and you're losing value and becoming too predictable; over 18% and you're playing marginal, drawing hands which require a fair bit of skill and experience to take advantage of.

Having said that, a more worthwhile list of %ages would be position stats. For example, someone with a VP of 18% maybe playing 26% of hands on the button but only 10% UTG, with a roughly straight line between the two. If you played 18% of hands in every position you would be giving up a LOT of value in position and getting yourself into losing plays out of position.