condition mean min max ZT0-3 5.593043333333334 4.205135 6.4714100000000006 ZT4-7 10.65525 10.65525 10.65525 ZT8-11 3.4036299999999997 3.4036299999999997 3.4036299999999997 ZT12-15 5.4148325 4.731335 6.098330000000001 ZT16-19 3.9998 3.9998 3.9998 ZT20-23 3.626515 3.626515 3.626515