condition mean min max ZT0-3 23.11175479 22.05855875 24.164950830000002 ZT4-7 29.2014876875 28.00015377 30.402821605 ZT8-11 40.349553202500005 33.565667085 47.13343932 ZT12-15 37.7044345925 33.964031065 41.44483812 ZT16-19 33.6523211075 32.97715737 34.327484845 ZT20-23 35.20162986 34.07458335 36.32867637