It's 9 and 3 if you have an airbag, according to the NHTSA.
Well, they're close, anyway. In the real world, around 8 and 4, or even 7:30 and 4:30 is a better choice when you're using two hands. It's been a LONG time since power steering obviated the need to ever use both hands to apply torque. Any but the most violent left turn can be easily accomplished solely with the right hand starting at 4 or 4:30, and any but the most violent right turn can easily be accomplished solely with the left hand starting at 7:30 or 8. With the hands starting low, there is much more available motion before you have to do hand-over-hand, and additionally it is safer in case the airbag goes off and tries to do you violent injury.
The unused hand only comes into play for extremely violent maneuvering; huge hand-over-hand steering inputs.
Most of the time on the highway, one hand at 12 or 1 is perfectly capable of making any required maneuvers. You can't apply huge inputs at highway speed without spinning out anyway.
For anybody who uses the seatbelt, the airbag is his worst enemy anyway. You don't want your arms anywhere near that damn thing when it goes off. Most definitely not above the center of the wheel, but better nowhere near it. Drivers who crash cars for a living always cross their arms over their chest just before impact so flailing arms won't shatter bones and gouge wounds if when they hit objects.
An airbag is not some kind of balloon that blows up fast, like in the cartoons. It has a goddam pyrotechnic inflator. That means explosive. Quicker than the blink of an eye. An airbag is a devastating weapon. If it saves the life of an imbecile who can't trouble to buckle up it MAY be worthwhile, but for anyone of normal intelligence it is a liability.