I have a db with people, salary, age, salary deferral amount.   I have a formula '@agegroup'  

If 17">{@RealAge}>17 and {@RealAge}<30 then '18 - 29'

etc, etc for grouping people by age range.  "18 - 29' is one of the groups. I need to summarize (average) each age group's salary deferral.

 

I realize this is simple with groups and sections but I need to display all the averages in report header.  I thought this would be a simple formula: average ({@salarydeferral},(@agegroup}, '18 - 29')

 

The formula results in the error "a group condition is not allowed here".

 

How can I create a formula, for the report header, that will give me a summary for each group.