Rework Only All Volunteer Report

The Only All Volunteer report in the spreadsheet download currently shows students who attended an All Volunteer training and then did not attend any other event. It should also have a list of students that went to an All Volunteer training and then did not earn any service hours. Each of those lists should then show the percentage of All Volunteer attendees.

This will require thinking about how to show more complicated data than headers and a list of rows. A general way to handle more complexity would be nice.