Show year where a track with a seating at least 5000 opened and a track with seating no more than 4000 opened.
return tracks ;return seating of #1 ;return #1 where #2 is  at least 5000 ;return #1 where #2 is  at most 4000 ;return #3 ,  #4 ;return year opened of #5
['select', 'project', 'comparative', 'comparative', 'union', 'project']