condition mean min max ZT0-3 1.3209225 1.0452825 1.589205 ZT4-7 1.0808369999999998 1.0808369999999998 1.0808369999999998 ZT8-11 1.31967 1.31967 1.31967 ZT12-15 2.858235 2.74477 2.9717000000000002 ZT16-19 2.6846249999999996 2.6846249999999996 2.6846249999999996 ZT20-23 2.315365 2.315365 2.315365