Raw scores are not reported to the schools the NBME only sends them a statistically adjusted standard score. For Clinical tests thus a score of 70 is 50th percentile. They always have a standard deviation of 8 I believe.
Here is a description from the NBME
Subject Examination scores are provided on a scale
that has been developed individually for each test
and are statistically equated across test administrations
to a common score scale. Scores are statistically
adjusted for shifts in test difficulty and consequently,
can be used to track school and student
performance over time. For the basic science disciplines,
the subject examination score is scaled to
have a mean of 500 and a standard deviation of
100 for a specific group of first–time takers who
took the examination as an end-of-course or endof-
year assessment. For the clinical science disciplines,
the subject examination scores are scaled
to have a mean of 70 and a standard deviation of
8 for a specific group of first-time takers who took
the examination as an end-of-clerkship examination.
It is important to note that although the
subject examination scores for the clinical science
examinations have the "look and feel" of percent correct
scores, they are not.
