condition mean min max ZT0-3 1.2628085 1.1597605 1.361355 ZT4-7 1.164898 1.164898 1.164898 ZT8-11 1.0950799999999998 1.0950799999999998 1.0950799999999998 ZT12-15 2.43161 2.3907249999999998 2.472495 ZT16-19 2.4122149999999998 2.4122149999999998 2.4122149999999998 ZT20-23 2.210635 2.210635 2.210635