We can't estimate the amount here, because of many reasons.
For example, there are local Garmin distributors who want to be more attractive for customers, so they rise 3760's functionality to 3790's and sell it for 3760's price. This is only a small example, of course, you can easily imagine a lot more possibilities. I've been working for such distributors long before turboccc have had published 37xx patch and I'm sure I'm NOT the only Garmin patcher in the world Also we can't estimate percent of such distributors among people downloading RGN_Tool.