condition mean min max ZT0-3 3.35 3.35 3.35 ZT4-7 4.9 4.9 4.9 ZT8-11 20.95 20.95 20.95 ZT12-15 33.7 33.7 33.7 ZT16-19 26.25 26.25 26.25 ZT20-23 42.7 42.7 42.7