It is unusual that all 5 people hired were female. But, remember that coincidences happen. There are plenty of schools in which all 15 people hired are male. Unless there is some reason why your school specifically would be set apart, I don't think this is anything more than a strange coincidence.
It's possible that something in the middle is going on -- a recruiter asked a professor for recommendations and he/she happened to recommend mostly women.
It's possible that something in the middle is going on -- a recruiter asked a professor for recommendations and he/she happened to recommend mostly women.