No, puffin, actually NCE 92 or 93 is always going to be 98th %ile, in a normally-distributed population. It isn't a peculiarity of this specific norm group. There will be some oddities comparing NCE to %ile if the data set is not normally-distributed, though.
Although I agree that %iles can be misleading, especially in a tightly-bunched group with outliers. Just like medians. It's just rank-ordering.
I go that after I read the post that crossed mine. I just couldn't be bothered deleting the whole thing. I was thinking of something else. Next time i will check the book first. Sorry.
