condition mean min max ZT0-3 6.7 6.7 6.7 ZT4-7 8.9 8.9 8.9 ZT8-11 2.85 2.85 2.85 ZT12-15 5.8 5.8 5.8 ZT16-19 24.15 24.15 24.15 ZT20-23 2.05 2.05 2.05