condition mean min max ZT0-3 9.374828 9.374828 9.374828 ZT4-7 8.371383 8.371383 8.371383 ZT8-11 9.453145 9.453145 9.453145 ZT12-15 10.6910855 10.6910855 10.6910855 ZT16-19 9.983420500000001 9.983420500000001 9.983420500000001 ZT20-23 10.425003499999999 10.425003499999999 10.425003499999999