condition mean min max ZT0-3 4.585476666666667 2.699365 6.28433 ZT4-7 2.12942 2.12942 2.12942 ZT8-11 3.76727 3.76727 3.76727 ZT12-15 3.37491 3.186045 3.5637749999999997 ZT16-19 6.07095 6.07095 6.07095 ZT20-23 5.9468 5.9468 5.9468