There's also the question of what a 'pilot' means. Do those stats cover all Australian licence holders, including overseas trainees that have learnt in Australia, or just cover Australian citizen pilots. Same for other nations. I would expect Australia to have a very low proportion of local pilots with CASA issued licences, private GA flying is virtually dead, and has been for years now. For a long time now 98% of everything you hear flying GA wise is a trainer, most likely training a foreign pilot. While there is nothing wrong with that, I would imagine GA would be 90% deader without that foreign input.