condition mean min max ZT0-3 2.126123333333333 1.438515 3.149115 ZT4-7 1.33509 1.33509 1.33509 ZT8-11 2.04387 2.04387 2.04387 ZT12-15 3.2062600000000003 3.12699 3.28553 ZT16-19 3.139135 3.139135 3.139135 ZT20-23 3.903285 3.903285 3.903285