1. how many artists/ people with a masters of fine arts in the united
states are able to make a living in art?
2.how many are waiting tables?
3.how does this compare with, say, germany?
this is 3 different questions.  i am trying to obtain some facts
regarding the difficulty of supporting yourself as an artist in the
united states despite high level of achievement.  and i'm trying to
find countries that do better for their artists/ ie offer livelihoods.
 and i'm trying to get facts and comparisons.

Most master degrees in fine arts don't qualify one as an artist,
someone producing "art": paintings, sculptures, photos, "happenings",
or whatever kind of visual art.
If this is your definition of "able to make a living in art", please confirm.

A degree in fine arts usually is a qualification to write about or
teach the subject.

Since you mention Germany  (where an academic degree is considered
qualification for professional work in the field), twenty-odd years
ago, graduates in art were trying to claim that since the state paid
for their university education it also owed them a job practicing what
they had learned.  Luckily, that demand wasn't met.