In addition to the above statistical facts, unless this lady *works in* the admissions office, there's no reason at all to think that she's giving you an accurate figure... You'll find at university that the world, and even the university, is a very large place, and people generally don't know very much of what happens outside of their specialized area (for instance, your Physiology lecturer would occasionally tell you stuff your Biochemistry lecturer would frown upon), so if this is just a promotion/information lady with no particular ties to the med school, one could argue that she wouldn't know the figures to start with.
As I said before, "person from Auckland" doesn't necessarily equate to "person from Auckland who knows what they're talking about". One of the things a university is supposed to develop in its students is independent thinking, and not just trusting whatever comes out of your teacher/lecturer's mouth, so when you get to the stage in life that I'm in right now, you'll be more and more doubtful and suspicious of what people tell you, which is part of the purpose of tertiary education.