[经] operating ratio based upon revenues

àn shōu rù zǒng é jì suàn de yíng yè bǐ lǜ ㄢˋ ㄕㄡ ㄖㄨˋ ㄗㄨㄥˇ ㄜˊ ㄐㄧˋ ㄙㄨㄢˋ ㄉㄜ˙ ㄧㄥˊ ㄧㄝˋ ㄅㄧˇ lv4