Display user data in numbered list

We sell a downloadable product. Each download requires registration and those who register for a download are assigned to a user role called “TFWPdownload”. The registrants are further subdivided by hospital with a custom plugin. We bill the hospitals monthly based on the number of downloads. I can pull up the “TFWPdownload” users and sort the list by hospital name but for billing purposes I have to count the number of users for a particular hospital by hand. Is there a way to have the sorted list in the users admin display a simple sequential number by each user starting with “1”? In other words, if the sort produced 256 users assigned the TFWPdownload user role the list would start at 1 and the last user would be 256.