Hi, yeyixin 9 out of 10 十分之九/九成 十分之九的人死于这个病. I think maybe "9 out of 10" is the main concern of your question. If you need more accurate translation. Then the privision of context would be helpful.

有九成人都是死于这种疾病 Nine out of (10 is assume, it can be omitted)

9成人死于这种疾病 or 百分之九十的人死于这种疾病

十人中有九人死于这种疾病。

十有八九的人都是死于这种疾病。