How many full-time administrative assistants for a philosophy department?

A colleague elsewhere writes:  "We’ve had two full-timer admins for 6 years.  One was assigned centrally to the day-to-day operations of the graduate program.  That admin left for a better paying job, and we were denied a request to hire a replacement.  The Dean’s judgment is that we do not need a second admin."   This philosopher wondered what the norm was.  To make this more concrete, this is a PhD program with about 15 full-time faculty, several lecturers, around 30 PhD students at any given time typically, and not quite 100 undergraduate majors.  For those working in PhD programs, what are the norms where you are--please give rough estimates about the size of the program along the lines of the preceding, as well as noting how much administrative support is available.