Graph to show percentage at value axis and display record count on top of bar

Hi,

I want to have graph which shows percentage instead of the number count of record to show at value axis.

Below are some of my setting:

1. The Graph type is Col(7).

2. Under Data tab, setting as below:

- Category = string(month (duedate))+"/"+string(year(duedate))

- Value = count(duedate for graph)

There is no option for me to select something to calculate percentage under "Value" here (as above).

3. Under Axis tab, Axis = Value, I have set it ScaleValue = Scale_Percentage, but it seem not calculate the value axis into percentage. You may refer to screenshot below for current result I have now, which showing count of record, instead of percentage. Example: in August (8/2015), there is 1339 records in my database.

And how can i show the record count on top of each bar? Same example as below, to show '1339' on top of '8/2015' bar.

Thank you.