condition mean min max ZT0-3 5.7 5.7 5.7 ZT4-7 6.7 6.7 6.7 ZT8-11 5.05 5.05 5.05 ZT12-15 8.8 8.8 8.8 ZT16-19 4.35 4.35 4.35 ZT20-23 8.85 8.85 8.85