I have the following calculation
=IIf(DLookUp("[PresDD]","[qryEnergy_Report_Data_(Table_10)]","[Name] = 'Main Campus' And [Utility] = 'Heating'") > DLookUp("[PrevDD]","[qryEnergy_Report_Data_(Table_10)]","[Name] = 'Main Campus' And [Utility] = 'Heating'"),"An increase in consumption of " &...