condition mean min max ZT0-3 37.723297 37.723297 37.723297 ZT4-7 46.8331535 46.8331535 46.8331535 ZT8-11 49.0743425 49.0743425 49.0743425 ZT12-15 40.8919525 40.8919525 40.8919525 ZT16-19 31.938340500000002 31.938340500000002 31.938340500000002 ZT20-23 37.875247 37.875247 37.875247