condition mean min max ZT0-3 26.0 26.0 26.0 ZT4-7 1.6 1.6 1.6 ZT8-11 8.95 8.95 8.95 ZT12-15 17.55 17.55 17.55 ZT16-19 18.0 18.0 18.0 ZT20-23 3.8 3.8 3.8