condition mean min max ZT0-3 3.2 3.2 3.2 ZT4-7 7.0 7.0 7.0 ZT8-11 15.6 15.6 15.6 ZT12-15 6.25 6.25 6.25 ZT16-19 33.9 33.9 33.9 ZT20-23 1.85 1.85 1.85