condition mean min max ZT0-3 2.8981149999999998 2.7190149999999997 3.0772150000000003 ZT4-7 3.80991 3.80991 3.80991 ZT8-11 3.6097400000000004 3.6097400000000004 3.6097400000000004 ZT12-15 0 0 0 ZT16-19 4.89897 4.89897 4.89897 ZT20-23 3.040465 3.040465 3.040465