An official study of the matter would be great. I'm not aware of that study being done. In the interim, then, commonsense will have to suffice: most NT scholars are Christians, and since history isn't a hard science, there's no rigorous method to weed out the bias that the practitioners naturally have. Most NT scholarship is therefore tilted in Christianity's favour. The more skeptical hypotheses about Jesus are dismissed as being outside the Overton window, rather than demonstrated to be improbable.