condition mean min max ZT0-3 2.85 2.85 2.85 ZT4-7 4.3 4.3 4.3 ZT8-11 6.9 6.9 6.9 ZT12-15 3.3 3.3 3.3 ZT16-19 3.25 3.25 3.25 ZT20-23 9.35 9.35 9.35