How do i get my dog to stop jumping over the fence?

How much exercise does he get a day both physical and mental as if you don't give him enough he will of course want to get out as he will be bored and full of energy. And if you leave him alone in the garden all day again he will get bored. Don't leave him outside alone. You are lucky so far he has come back or hasn't been hit by a car or picked up and taken to the pound.