condition mean min max ZT0-3 42.9 42.9 42.9 ZT4-7 6.7 6.7 6.7 ZT8-11 13.0 13.0 13.0 ZT12-15 8.95 8.95 8.95 ZT16-19 27.75 27.75 27.75 ZT20-23 25.35 25.35 25.35