condition mean min max ZT0-3 3.3362999999999996 3.3362999999999996 3.3362999999999996 ZT4-7 1.387175 1.387175 1.387175 ZT8-11 2.431495 2.431495 2.431495 ZT12-15 4.473425 4.473425 4.473425 ZT16-19 8.215114999999999 8.215114999999999 8.215114999999999 ZT20-23 5.32272 5.32272 5.32272