How many more people were there in 2015 than in births and deaths in the last census?
return people ;return #1 in   2015 ;return number of  #2 ;return the  last census ;return births of #4 ;return deaths of #4 ;return number of  #5 ;return number of  #6 ;return sum of #7 and  #8 ;return the  difference of #3 and  #9
['select', 'filter', 'aggregate', 'select', 'project', 'project', 'aggregate', 'aggregate', 'arithmetic', 'arithmetic']