Dear Professor-Who-Shall-Remain-Anonymous,

A lab that has consistently only one female member over the years is not a lab that is "bucking the trend" (the trend that you have helpfully pointed out as having 60% of the incoming grad students be female), it's a lab that has failed to buck the convention, since the convention , anywhere from 20-50 years ago, is a ratio of something like one female per medium sized lab.

Sincerely,

Me.