10 December 2013
Percent is nothing but denotation of object in share of 100.
In Excel 2007 to 2013 in HOME ribbon 4th TAB / Block is of Number having % Sign.
If you want to represent net profit percent and x is net profit y is sales then in formula bar press = x / y. After pressing enter again select the sale having above formula and then by mouse click % sign in Number tab. In same tab by pressing left aero key select decimal point up to which value is desired.