condition mean min max ZT0-3 9.32201 6.19435 12.11215 ZT4-7 5.577795 5.577795 5.577795 ZT8-11 7.971195 7.971195 7.971195 ZT12-15 17.3739 17.00165 17.74615 ZT16-19 13.7049 13.7049 13.7049 ZT20-23 19.6244 19.6244 19.6244