RP projections based on CAD seats

From: Joseph Allison (Solid Concepts  Inc)
To: RP-ML
Date: Monday, December 11, 1995
Subject: RP projections based on CAD seats
     For the large part, the potential size of the market place that all us RPers are in, depends on the number of CAD seats out there that can generate STL files.  So far, all I have seen is market projections based on the total number of CAD seats.  This includes a large number of 2D and 3D wireframe modelers.  Also, many surface modelers that are intended strictly for NC toolpath generation, commercial graphics, and other such uses that do not require fully enclosed models.
     I have some questions:
     Does anyone know the number of world wide CAD seats that can generate STL files?
     And, are there any market projections based on this number?
     As I come to realize that the rest of my professional life will probably be devoted to Rapid Prototyping, I find this kind of information to be increasingly important.