condition mean min max ZT0-3 5.430818333333334 4.497 6.690110000000001 ZT4-7 3.3384 3.3384 3.3384 ZT8-11 2.388565 2.388565 2.388565 ZT12-15 2.4970999999999997 2.28051 2.7136899999999997 ZT16-19 3.904785 3.904785 3.904785 ZT20-23 5.480645 5.480645 5.480645