condition mean min max ZT0-3 17.737274999999997 16.231299999999997 19.24325 ZT4-7 15.84065 15.84065 15.84065 ZT8-11 13.04308 13.04308 13.04308 ZT12-15 0 0 0 ZT16-19 18.2431 18.2431 18.2431 ZT20-23 12.90435 12.90435 12.90435