The beast mode below is not calculating correctly in the Grand Total Column.
CASE WHEN SUM(IFNULL(`Billed Amount`,0)) = 0
THEN 0
ELSE
(((SUM(IFNULL(ABS(`Billed Amount`),0))) - (SUM(IFNULL(`Actual Material Cost`,0)) + (SUM(IFNULL(`Actual Labor Cost`,0))))))
/
SUM(IFNULL(`Billed Amount`,0))
END