condition mean min max ZT0-3 9.213727 9.213727 9.213727 ZT4-7 8.412628 8.412628 8.412628 ZT8-11 8.538931000000002 8.538931000000002 8.538931000000002 ZT12-15 8.278758 8.278758 8.278758 ZT16-19 7.593668 7.593668 7.593668 ZT20-23 8.361025 8.361025 8.361025