Stop loop or not?

I’ve got a simple function that works towards a lesson progress bar.

onEnterFrame = function () {
progTotal = Math.round (_root._totalframes);
progCurrent = Math.round (_root._currentframe);
progPercent = (progCurrent/300);
trace(progPercent);
}

Works like a champ, but as I traced it I noticed this occurs about 15 times a second (15fps).

This seems like a ton for overhead computing to me, and was wondering if I could just grab it initially on the enterframe and stop. I only need to know once in the frame when it changes (on the entry of a new frame).

Ideas?

Thanks.