Return the average, minimum, maximum, and total transaction amounts.
return transactions ;return amounts of  #1 ;return average of  #2 ;return minimum of  #2 ;return maximum of  #2 ;return sum of  #2 ;return #3 ,  #4 ,   #5 , #6
['select', 'project', 'aggregate', 'aggregate', 'aggregate', 'aggregate', 'union']