On a scale one to ten how bad is the black mould in my bathroom?

I posted about this before about 4 or 5 months ago the mould has gotten worse it has been reported to the council they are coming out on the 21th of this month the bathroom was painted a year or two but the mould has come back through three is no Extractor fan in the bathroom we recently found the key for the window we open it as much as possible