All right... I'm not entirely sure I understand what you want, but here goes nothing...
Without creating any custom charts, here's what you do. Look at the first image I posted above and find the link for "Sales by Book so far this Month" on your Reports dashboard. Click on that link.
Now look to the lower left of your screen. You should see this:
Where it says "Interval," click on the arrow next to "This Month." You should see a menu pop up:
Then you select "Custom" and set your start and end dates to whatever you want. This will display the number of each book sold per that time period. You can set it for any month you want for as far back as your account has existed.
I hope that helps.