How many years passed between the Jin dynasty and the Song dynasty?
return the  Jin dynasty  ;return the  Song dynasty  ;return years of #1 ;return years of #2 ;return the  highest of #3 ;return the  lowest of #4 ;return the  difference of #5 and  #6
['select', 'select', 'project', 'project', 'aggregate', 'aggregate', 'arithmetic']