KU does not show in daily trends.  It only shows in your statement details.  To investigate, you pull the Sales Details. 

In your dashboard, go to Reporting & Financials. 
Then go down to Sales and click Details
Select the sales detail dates matching the statement. Here, I've done two months.  Then select Yes for eBook Flag.  
Export the report, and filter by Discount percentage, then retailer.  Anything in the 90% range at Amazon is likely a KU read.