condition mean min max ZT0-3 2.8828750000000003 2.8828750000000003 2.8828750000000003 ZT4-7 2.466565 2.466565 2.466565 ZT8-11 2.137345 2.137345 2.137345 ZT12-15 2.18648 2.18648 2.18648 ZT16-19 3.8766249999999998 3.8766249999999998 3.8766249999999998 ZT20-23 3.344475 3.344475 3.344475