condition mean min max ZT0-3 0.9878511666666667 0.4551085 1.69771 ZT4-7 0.809237 0.809237 0.809237 ZT8-11 3.75661 3.75661 3.75661 ZT12-15 2.395325 0.92544 3.8652100000000003 ZT16-19 2.4113455 2.4113455 2.4113455 ZT20-23 3.550055 3.550055 3.550055