Grumps
Thanks, I found that data as well - good old FAA! The number I am looking for is for commercial helicopter pilots so I reckon that is around 22,000 which is 0.007% of the US population.
If you factor that to take account of the fact that the US is probably the most aviation oriented country in the world then we could have a global number closer to say 0.001% (China and India being the most populous but arguably with the least aviation oriented percentage).
If we take the global population at 7 billion (7,000,000,000) then 0.001% produces the number 70,000.
That about as good a guess as possible I reckon.
G.