It’s an interesting question. I suspect the true answer is in the 0.00X % figures.
Amongst the lurkers on here slightly higher and amongst the active contributing members much, much higher. As to who has regularly paid full freight F amongst us though that would be very small numbers, we know better than that
I'd mostly agree with this. I feel it can't be above 0.01%.
Quick back of envelope math: QF flies five flights a day with a true F out of Australia currently (SYD-DFW, SYD-LAX, MEL-LAX, MEL-DXB, SYD-DXB, ignoring SYD-HKG as not F service). These have 14 seats each. This is just over 25,000 F seats per year, one-way. 25,000 is just over about 0.1% of the total population of Australia. Of course, seats go empty, and people from other countries are in these seats as well. And, surely, many of these flyers are repeat flyers who have flown F before, with a number of them repeat flyers from the previous 12 months even. Of course, there are other carriers flying F into and out of Australia, but this is just to give an idea of the numbers.
Then again, not only have I flown F a number of times, but I've actually flown every currently flying QF F route (darn SIN switch is going to mess that up!)...but I'm also American and not Australian so that doesn't help the numbers, and in fact hurts them by blocking that many Aussies from those seats I was in

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