I'll take a wild guess and say that this is what I would expect to see, except for the American air force. I'm sure it's the same thing in the Canadian air force. There is so much emphasis placed on making sure that people are not fatigued, that they're well rested, that they can operate during long flights in different kinds of missions. Those are probably the 10% of the people who have protected time for sleep in the air force, and the rest of the service members will have much less than the six hours.
On November 26th, 2013. See this statement in context.