condition mean min max ZT0-3 18.2655 18.2655 18.2655 ZT4-7 13.4069 13.4069 13.4069 ZT8-11 13.899750000000001 13.899750000000001 13.899750000000001 ZT12-15 20.488599999999998 20.488599999999998 20.488599999999998 ZT16-19 30.764899999999997 30.764899999999997 30.764899999999997 ZT20-23 22.1328 22.1328 22.1328