Form Response records associated with Default Contact should be updated to an actual Contact.
For more information about how these get created in your system, see Default Contacts.
The Customer Portal Report Card gives an A grade when you have a decrease of at least 5% from previous month (or none). The number counted is Form Response records associated with Default Contact.
This tool is able to help assign a Contact with the Form Response if it is associated with an Event.
For the following type of form usages, the default Form Responses will need to be edited to the appropriate contact. If needed, a Contact record may need to be created via the Add/Edit Family tool.