condition mean min max ZT0-3 1.1153031666666666 0.4201995 1.716735 ZT4-7 0.653586 0.653586 0.653586 ZT8-11 0.413638 0.413638 0.413638 ZT12-15 0.8360322499999999 0.6458254999999999 1.026239 ZT16-19 1.462748 1.462748 1.462748 ZT20-23 0.9370125 0.9370125 0.9370125