condition mean min max ZT0-3 6.4280816666666665 5.240995 7.44634 ZT4-7 5.579155 5.579155 5.579155 ZT8-11 5.1825849999999996 5.1825849999999996 5.1825849999999996 ZT12-15 5.029335 4.8968799999999995 5.16179 ZT16-19 6.543615 6.543615 6.543615 ZT20-23 7.902055 7.902055 7.902055