What is the range of contributory negligence in a motor vehicle accident involving a child as young as 10?

With respect to contributory negligence, the plaintiff submits that the action by the child has to be egregious before 50% of the negligence can be attributed to the child. In the case of Bese (Next friend of) v. Mayan, the plaintiff was 10½ years old. 33⅓% was attributed to the child. In the case of Sharp v. Binder, the child who was then 12 years old was assessed 25% negligent, the court indicating that they are taking into consideration the age of the victim and therefore the duty on the part of any driver to predict some less than perfect behaviour on the part of children. It is the submission of the plaintiff that the appropriate range of contributory negligence would be somewhere between 0% and 33⅓%.