How many more percentage was the graduation class was employed by by nine months after graduation than secured positions in one nations largest firms?
return the  graduation  class ;return #1 that was  employed by nine months after graduation ;return #1 that secured positions in  one of the  nations largest firms ;return percentage of #2 ;return percentage of #3 ;return the  difference of #4 and  #5
['select', 'filter', 'filter', 'project', 'project', 'arithmetic']