If you take 100 different MBTI tests and score 100% on all of them, the chances of you being 100% N is very very unlikely..
It's not that clean cut and dry, everyone has every type in them, and we all use every function everyday. There are times when I use my I, my S, my T, and my J. Your type is only there to represent where the majority of your personality comes from.
It's completely insane to claim that you're 100% a certain type because you took a stupid 75 question test on it..It's like an IQ test..they give you a few narrowed down questions that focus on only a few strands of intelligence, and automatically define your IQ. Tests cover so little of your personality that it's insane that you can believe your 100% something.
As for me, I hover, mostly, around the NP types..my personality can show INTP, ENTP, INFP, and ENFP..it just so hapens that I am more like an ENFP.