Hi Mike

If you keep transaction history (and everybody should because there is no downside to not doing it), then the utility Toolkit for Adagio by Dakota Software (www.dakotasoftware.com) can retroactively compute the correct sales figures for you, with press of a proverbial button.

Yes, I realize that Toolkit for Adagio costs money, but your effort is worth something, and there is also a greater chance that you will do something wrong the way you are trying to do it.

If you already own Toolkit for Adagio, it's a slam dunk.

Steve