Report Table Tool - Add Border Every Nth Row

[hellyars]

I am using a report table tool. 

My data comes in groups of 3 (rows).   

Default Table Settings >> Style Editor >> Data >> Rows Per Group is set to 3.  This sets the Alternate Color (row banding) to 3.

Now I want to draw a border between each group of 3 rows.  How can I do this? 

[hellyars · Accepted solution]

Found it.  Under >> Borders >> Row Borders >> Group.  It was a leap of faith, but it works.