VB.net XML Serialization/Deserialization, How to Put Attributes for Lists

If I wanted to serizlize and deserialize an XML like this in VB:

  <SeveralListsOfPeople>
      <ListOfPeople groupname="Friends">
          <Person name="John">
          </Person>
          <Person name="Mary">
          </Person>
      </ListOfPeople>
      <ListOfPeople groupname="Family">
          <Person name="Karen">
          </Person>
          <Person name="Kyle">
          </Person>
          </ListOfPeople>
      <ListOfPeople groupname="Enemies">
          <Person name="Ben">
          </Person>
          <Person name="Chris">
          </Person>
      </ListOfPeople>
    </SeveralListsOfPeople>

How would I add the attribute to "SeveralListsOfPeople"? I can't figure out how to add attributes to lists or arrays.