condition mean min max ZT0-3 7.8741746855 6.956236172 8.792113199000001 ZT4-7 8.763618512833334 8.740697763 8.786539262666668 ZT8-11 6.797458699833333 6.554719486 7.040197913666667 ZT12-15 7.056535574333333 5.990618497666667 8.122452651 ZT16-19 7.633314976833334 7.499285674666667 7.7673442790000005 ZT20-23 9.931698255333334 9.612494160999999 10.250902349666667