Display calculated data in report but getting last value in every row

Hi i am trying to calculate the sync duration but issue is that its display last value in every row.

IF "WMS Activity Log".FIND('-') THEN REPEAT
IF "WMS Activity Log"."Action Type" = 'SyncStart' THEN BEGIN
CurrentUser := "WMS Activity Log"."User ID";
StartTime := "WMS Activity Log"."Date Time";

IF "WMS Activity Log".FIND('>') THEN
IF "WMS Activity Log"."Action Type" = 'SyncEnd'THEN
If NextUser = CurrentUser then
NextUser := "WMS Activity Log"."User ID";
EndTime := "WMS Activity Log"."Date Time";
TotalDuration := EndTime - StartTime;
END;

UNTIL ("WMS Activity Log".NEXT =0);