condition mean min max ZT0-3 4.5414900000000005 3.702335 4.98296 ZT4-7 5.61263 5.61263 5.61263 ZT8-11 5.455725 5.455725 5.455725 ZT12-15 6.1177125 5.378755 6.856669999999999 ZT16-19 6.218625 6.218625 6.218625 ZT20-23 6.25942 6.25942 6.25942