Bug
ContributorStats.__init__ unconditionally sets new_contributor = False on line 51 of contributor_stats.py, overwriting the value passed by the caller:
def __init__(self, username, company, new_contributor, ...):
new_contributor = False # ← bug: overwrites the parameter
...
self.new_contributor = new_contributor
This means any caller passing new_contributor=True will silently have it ignored.
Expected behavior
self.new_contributor should store the value passed by the caller.
Fix
Remove the new_contributor = False reassignment on line 51.