condition mean min max ZT0-3 14.7778 13.49785 16.05775 ZT4-7 13.2819 13.2819 13.2819 ZT8-11 17.496299999999998 17.496299999999998 17.496299999999998 ZT12-15 0 0 0 ZT16-19 31.0505 31.0505 31.0505 ZT20-23 22.172649999999997 22.172649999999997 22.172649999999997