condition mean min max ZT0-3 3.9760633333333333 3.00983 4.51981 ZT4-7 5.445705 5.445705 5.445705 ZT8-11 3.764235 3.764235 3.764235 ZT12-15 4.9449925 4.9369250000000005 4.95306 ZT16-19 4.28309 4.28309 4.28309 ZT20-23 4.59689 4.59689 4.59689