Find the average age and experience working length of journalists working on different role type.
return journalists ;return role types of #1 ;return ages of #1 ;return experience working lengths of #1 ;return the  average of #3 for each #2 ;return the  average of #4 for each #2 ;return #5 ,  #6
['select', 'project', 'project', 'project', 'group', 'group', 'union']