How many more touchdowns were scored in the first half compared to the second half?
return touchdowns ;return #1 that were scored in  the  first half  ;return #1 that were scored in  the  second half  ;return number of  #2 ;return number of  #3 ;return difference of #4 and  #5
['select', 'filter', 'filter', 'aggregate', 'aggregate', 'arithmetic']