How many more million people were poor in 2014 than 2015?
return people ;return #1 that were poor in  2014 ;return #1 that were poor in  2015 ;return number of  #2 ;return number of  #3 ;return the  difference of #4 and  #5
['select', 'filter', 'filter', 'aggregate', 'aggregate', 'arithmetic']