IO,
There are several very different types of 'bust' and I believe GPS use figures very differently for the different types.
There is the -
straight through a restricted area (or a TRA) - this is probably more about planning/notams and/or using a camping GPS that doesn't show your position on an aviation map.
A bust by 1/2 mile from someone creeping around the edge of the airspace (almost surely a GPS user and maybe not even a bust)
Flying through 'Heathrow's overhead' - ie. really quite far out of position - which is almost always DR based navigation.