condition mean min max ZT0-3 14.894116666666667 13.95965 16.5963 ZT4-7 16.54895 16.54895 16.54895 ZT8-11 23.0141 23.0141 23.0141 ZT12-15 23.206525 22.9132 23.49985 ZT16-19 20.02765 20.02765 20.02765 ZT20-23 19.71075 19.71075 19.71075