Cross Tab Crystal Report XI

HELP!

I am not a programmer, but trying to learn so I can help hour HR Dep.

I am using a cross tab to create a report.

Group by: Dept 1, Dept 2, Dept 3, etc.,
Row 1: No of authorized positions.
Row 2: No of filled (hired)
Row 3: I want to display % filled (hire)

I created a formula for Row 3 but I am gating percent from Grand total not the each group total. How can I get percent from each group Row2 divided by Row1 to display in the Row 3.