condition mean min max ZT0-3 17.488100000000003 17.488100000000003 17.488100000000003 ZT4-7 7.9678249999999995 7.9678249999999995 7.9678249999999995 ZT8-11 12.117 12.117 12.117 ZT12-15 28.25205 28.25205 28.25205 ZT16-19 25.667749999999998 25.667749999999998 25.667749999999998 ZT20-23 20.69455 20.69455 20.69455