Let me explain it in easier terms. What is more likely to

Let me explain it in easier terms. What is more likely to kill a person, 1 bullet or 100 bullets?

How can a company advertise their bullet proof vest with 95% survival rate if they tested it only under special conditions (small caliber, getting hit by just one shot).
My question is, what about bigger caliber ammo and being shot hourly several times? Only that shows the real efficacy. The rest is pseudo science.