condition mean min max ZT0-3 20.341749999999998 19.17585 21.507649999999998 ZT4-7 19.816850000000002 19.816850000000002 19.816850000000002 ZT8-11 18.8599 18.8599 18.8599 ZT12-15 0 0 0 ZT16-19 15.9413 15.9413 15.9413 ZT20-23 16.4618 16.4618 16.4618