I don't believe there is a nation-wide, NFHS minimum score available, I think it is dependent on your local associations. In IL, for example, there is a state-wide minimum score of 80 on the open book exam to get a license. Then there are other minimums on closed-book exams for promotions to various levels. There might also be local associations that use the exam for promotions and assignments.
So, the very specific answer to your question is: it depends.
