condition mean min max ZT0-3 23.397751 23.397751 23.397751 ZT4-7 17.511127 17.511127 17.511127 ZT8-11 15.4526165 15.4526165 15.4526165 ZT12-15 13.936253 13.936253 13.936253 ZT16-19 18.5021385 18.5021385 18.5021385 ZT20-23 15.868876 15.868876 15.868876