What are the names of artist whose exhibitions draw over 200 attendees on average?
return artists ;return exhibitions of  #1 ;return attendees of  #2 ;return number of  #3 for each  #1 ;return average of  #4 ;return #1 where #5 is  higher than 200 ;return names of  #6
['select', 'project', 'project', 'group', 'aggregate', 'comparative', 'project']