condition mean min max ZT0-3 3.692 3.2348749999999997 4.299065000000001 ZT4-7 6.1747 6.1747 6.1747 ZT8-11 6.0964100000000006 6.0964100000000006 6.0964100000000006 ZT12-15 17.336325 17.190649999999998 17.482 ZT16-19 11.7487 11.7487 11.7487 ZT20-23 8.097585 8.097585 8.097585