Not quite sure, but I guess it's total population. It may not be exactly 400 but maybe 380 oder 450, I cannot know for sure. The only source I have says it's "a village of roughly 400 peasants". Maybe I just divide 400 by 6 or something like it, should equal about 60 homes or so. Seems quite realistic to me considering that peasant households might be bigger while craftsmen might only live together with their wive or so.