condition mean min max ZT0-3 21.5 21.5 21.5 ZT4-7 8.8 8.8 8.8 ZT8-11 25.55 25.55 25.55 ZT12-15 34.9 34.9 34.9 ZT16-19 30.85 30.85 30.85 ZT20-23 57.2 57.2 57.2