condition mean min max ZT0-3 2.8 2.8 2.8 ZT4-7 5.6 5.6 5.6 ZT8-11 8.05 8.05 8.05 ZT12-15 3.1 3.1 3.1 ZT16-19 4.35 4.35 4.35 ZT20-23 5.0 5.0 5.0