condition mean min max ZT0-3 1.595475 1.595475 1.595475 ZT4-7 1.4223249999999998 1.4223249999999998 1.4223249999999998 ZT8-11 0.8841939999999999 0.8841939999999999 0.8841939999999999 ZT12-15 2.39538 2.39538 2.39538 ZT16-19 2.07627 2.07627 2.07627 ZT20-23 2.2908549999999996 2.2908549999999996 2.2908549999999996