condition mean min max ZT0-3 4.601728333333334 4.24843 5.2965800000000005 ZT4-7 4.75001 4.75001 4.75001 ZT8-11 3.6812 3.6812 3.6812 ZT12-15 4.223115 3.723585 4.722645 ZT16-19 3.2388450000000004 3.2388450000000004 3.2388450000000004 ZT20-23 4.456055 4.456055 4.456055