What are the average, minimum, and maximum ticket prices for exhibitions that happened prior to 2009?
return exhibitions ;return #1 that  happened prior to 2009 ;return ticket prices for #2 ;return average of  #3 ;return minimum of  #3 ;return maximum of  #3 ;return #4 ,  #5 ,   #6
['select', 'filter', 'project', 'aggregate', 'aggregate', 'aggregate', 'union']