condition mean min max ZT0-3 20.984049999999996 18.211599999999997 23.7565 ZT4-7 23.867 23.867 23.867 ZT8-11 6.247295 6.247295 6.247295 ZT12-15 0 0 0 ZT16-19 19.472749999999998 19.472749999999998 19.472749999999998 ZT20-23 54.27515 54.27515 54.27515