What is the name and the average gpa of department whose students have the highest average gpa?
return departments ;return students of  #1 ;return gpas of  #2 ;return average  of  #3 for each  #1 ;return #1 where #4 is  highest ;return name of  #5 ;return students of  #5 ;return gpas of  #7 ;return average  of  #8 ;return #6 ,  #9
['select', 'project', 'project', 'group', 'superlative', 'project', 'project', 'project', 'aggregate', 'union']