condition mean min max ZT0-3 20.809874999999998 18.26265 23.3571 ZT4-7 14.8698 14.8698 14.8698 ZT8-11 15.343699999999998 15.343699999999998 15.343699999999998 ZT12-15 0 0 0 ZT16-19 17.77375 17.77375 17.77375 ZT20-23 20.92955 20.92955 20.92955