How many more people are there between 30 and 49 are there than there are people who are 80 and over?
return people ;return #1 that are   between 30 and  49 ;return #1 that are   80 and  over ;return number of  #2 ;return number of  #3 ;return difference of #4 and  #5
['select', 'filter', 'filter', 'aggregate', 'aggregate', 'arithmetic']