condition mean min max ZT0-3 11.963331666666667 8.987645 14.422 ZT4-7 7.4795 7.4795 7.4795 ZT8-11 9.24396 9.24396 9.24396 ZT12-15 17.7367 16.6202 18.8532 ZT16-19 13.7778 13.7778 13.7778 ZT20-23 14.3864 14.3864 14.3864