condition mean min max ZT0-3 5.55 5.55 5.55 ZT4-7 3.8 3.8 3.8 ZT8-11 9.85 9.85 9.85 ZT12-15 21.95 21.95 21.95 ZT16-19 41.45 41.45 41.45 ZT20-23 37.65 37.65 37.65