condition mean min max ZT0-3 1.9863524135000001 0.823330063 3.149374764 ZT4-7 4.7663436315 3.3835827565 6.1491045065000005 ZT8-11 11.262153912999999 7.483803994 15.040503831999999 ZT12-15 17.46076398 16.22411987 18.69740809 ZT16-19 22.120004429999998 21.53417785 22.705831009999997 ZT20-23 24.22055977 23.75719901 24.68392053