How to calculate a pivot table and its bar graph in percentage instead of values?

Hi all,

In the attached file, sheet "Pivot-Closed" contains a pivot as nRFT below cell E25.

Feb month shows count as 4. Apart from the value, i also want that it should show percentage. Percentage is to be calculated by dividing cell F28 by F19 thus giving a result of 1.74%

This should continue for subsequent months such as the count of March under nRFT should be divided by Tasks Closed in March and so on.

Further, this percentage should be displayed in a bar graph in the sheet Graph.

Can someone let me know how to create such a pivot?

Many thanks