How many more field goals did Kaeding make than Mehlhaff?
return Kaeding ;return Mehlhaff ;return field goals of #1 ;return field goals of #2 ;return number of  #3 ;return number of  #4 ;return difference of #5 and  #6
['select', 'select', 'project', 'project', 'aggregate', 'aggregate', 'arithmetic']