condition mean min max ZT0-3 7.5269332525 7.339014296 7.714852209 ZT4-7 8.537905978000001 8.46753144 8.608280516 ZT8-11 8.665782922666667 8.432414094666667 8.899151750666666 ZT12-15 9.3313890885 9.074938121333334 9.587840055666668 ZT16-19 9.197861652666667 8.837873805333333 9.5578495 ZT20-23 9.7427220615 9.495807935 9.989636188