You need to change the query, make a virutal field with a home grown function.
In vbe, INSERT, MODULE,
then paste this code.
Save
In the query, in a new column, AgeGrp([age]) (if you have a field called age, or calculate age in it: datediff("y",date1,date())
Code:
Public Function AgeGrp(byval pvAge)
If pvAge >= 16 And pvAge <= 24 Then
AgeGrp = "16 - 24"
ElseIf pvAge >= 25 And pvAge <= 34 Then
AgeGrp = "25 - 34"
ElseIf pvAge >= 35 And pvAge <= 44 Then
AgeGrp = "25 - 34"
ElseIf pvAge >= 45 And pvAge <= 54 Then
AgeGrp = "25 - 34"
ElseIf pvAge >= 55 And pvAge <= 64 Then
AgeGrp = "25 - 34"
ElseIf pvAge > 64 Then AgeGrp = "65+"
End Function