Give me a break. Don't mess with Jones fracture. The blood supply to the 5th metatarsal can be poor in some individuals. The stress applied to the metatarsal in an area where flexible bone meets rigid bone tends to welcome fractures. Care must be taken to take enough stress off the fracture to insure the best chance for healing. The best estimation is that about 75% of Jones fractures will heal without incident.
Varies. Once a jones fracture is completely healed, there is usually not a very high likelihood that it will happen again. The main exception to this is if you have some form of foot deformity that places more stress on the fifth metatarsal. In my practice, it is rare to see a person have a jones fracture, heal it, and then go on to have another one.
Who tracks that? I have no idea if anyone even tracks that statistic. Of course, one could refracture a bone if it never really healed in the first place or if the same mechanism of injury recurs because the foot lacked proper support for the activity engaged. Best would be to finally seek proper care in order to avoid another occurence.