I was wondering the same thing. I have no idea, and I am thinking about leaving it blank.
I received about 4200 in grant money. This lowered my tuition to 12k (roughly).
From the info they gave at orientation, the median LSAT was 161, and I forgot the GPA, but I think it was in the 3.5-3.6 range (median).
I had numbers lower than both of these medians, and was accepted, if that helps any.