Why not try the NBAA (National Business Aviation Association) as a starting point. There's been market research done on this kind of thing before (supersonic business jet) by manufacturs, and NetJets would represent only some, by no means all, the long-range private flying being done out there.
NJI etc might give you some numbers, or not, but corporate flight departments aren't going to tell you a thing about where and how often they're flying. The NBAA may collect the non-specific, general statistics of thier membership as part of their overall effort to promote business aviation.
Last edited by PukinDog; 25th Apr 2012 at 16:57.