condition mean min max ZT0-3 25.85 25.85 25.85 ZT4-7 5.3 5.3 5.3 ZT8-11 8.65 8.65 8.65 ZT12-15 20.25 20.25 20.25 ZT16-19 12.85 12.85 12.85 ZT20-23 19.7 19.7 19.7