Creating a report based on Account (Customer)

Creating a report based on Account (Customer)

We would like to be able to create a report (and have it displayed in the dashboard) that shows the number of requests that each of our customers (i.e. Accounts) have submitted.  But when I create a new report and try to customize it, under the "Grouping" tab, "Account" is not an option in the "Summarize information by..." dropdown menu. I have tried and tried to figure out how to add a field so that "Account" will be an option in this dropdown, but without success.  Is there a way to do this?

Thanks much.