condition mean min max ZT0-3 5.5773 5.5773 5.5773 ZT4-7 3.88429 3.88429 3.88429 ZT8-11 3.12685 3.12685 3.12685 ZT12-15 5.49201 5.49201 5.49201 ZT16-19 6.716795 6.716795 6.716795 ZT20-23 4.591585 4.591585 4.591585