Drop meaningless percentage convertion in Excel formula
Use array notation in formula when expanding range

This is necessary for instance for SUMIF(). SUM() can have as many arguments
as necessary, but SUMIF() can only have exactly 2 or 3 arguments. The workaround
to expend range and still use SUMIF() is to use array notation.

Also see http://office.microsoft.com/en-us/excel-help/more-arrays-introducing-array-constants-in-excel-HA001087291.aspx