SAP Crystal Report - Formula in Cross Tab Report

I have a below requirement in a cross tab report,

Category Name Valu1 Value2 %ge

-

A Car 40 50 80

A Bike 30 60 50

Total 70 110 63.6

%ge is a formula field and is calculated as value1/value2 * 100

Consider the Total section as a group footer.

In the cross tab report how do I put the formula field for %ge in Total section.