condition mean min max ZT0-3 9.680976 9.680976 9.680976 ZT4-7 9.245763 9.245763 9.245763 ZT8-11 8.973618 8.973618 8.973618 ZT12-15 9.4511275 9.4511275 9.4511275 ZT16-19 9.5219125 9.5219125 9.5219125 ZT20-23 10.866541999999999 10.866541999999999 10.866541999999999