condition mean min max ZT0-3 20.45 20.45 20.45 ZT4-7 8.0 8.0 8.0 ZT8-11 26.8 26.8 26.8 ZT12-15 39.5 39.5 39.5 ZT16-19 25.35 25.35 25.35 ZT20-23 4.0 4.0 4.0