Thirteen
Most Hermit images have him looking ahead....
So...why do you say the Hermit is looking back?
I'm curious as to why you say that. In this Marseilles deck cards (https://s-media-cache-ak0.pinimg.com/736x/dc/24/9e/dc249ef360e85c134bd289d31c22b7a7.jpg), the Hermit is very clearly looking forward. Eyes open and focused on what is in front of him. Meanwhile, in the RWS Hermit card (http://www.learntarot.com/bigjpgs/maj09.jpg) he seems to have his eyes either lowered and looking down at what his lantern is illuminating in front of his feet, or closed and head bent in meditation (perhaps about whatever he just saw by the light of his lantern?). And in the very cool Thoth Hermit (https://www.e-act.nl/admin/img/94/Image/kluizenaar.jpg) we see the Hermit's back, including the back of the head. He's not only looking ahead, but moving in that direction. His lantern (interestingly!) is back as if saying, "I'm lighting the way for you. Follow me into the future!"The Hermit is looking back to see where he has come from. Maybe a location would be somewhere nostalgic. Somewhere you visit but you really can't return to because you have outgrown it.
So...why do you say the Hermit is looking back?