Cessna production in 1978: 9700 piston airplanes in 42 different models
The Permit side of GA has been doing well for many years - think how many shiny new Van's aircraft are around.
New, less regulated, aircraft seems to be the only way light aviation in general is going to survive.
But really Rod? Only 8000 Vans kits have been built in total, that might keep aviation ticking over but it is not the answer. And, to be honest, I am not going to trust my ar*e to a kit plane someone else built and I don't have time to build my own.
The only way to go is less regulation / bigger "microlights" (bigger as in 4 seats and the size of a PA-28, not 4 seats for midgets and the size of a Banbi).