[经] ratio of total expenses to total revenues

zǒng fèi yòng duì zǒng shōu rù de bǐ lǜ ㄗㄨㄥˇ ㄈㄟˋ ㄩㄥˋ ㄉㄨㄟˋ ㄗㄨㄥˇ ㄕㄡ ㄖㄨˋ ㄉㄜ˙ ㄅㄧˇ lv4