Product Stats: Why do I only see today's data?
You are able to perform grouping on the Product Stats page. Go to the Main Menu > Product > Product Stats use the Smart Search filter and change the date(s). You are able to use this page to group your products. There are arrows at the top of each category you can use to sort your product the way you want to see them. I've enclosed a link to learn how to sort products. Product Stats: How To Sort Results
You can also export your search results to an excel document by clicking Action > Export Products. Go back to the Main Menu and click Reports > Download Exports click the green Download button and the report will export to an excel file. Add filters to your excel sheet and and than use the SUM formula to add up the values.