condition mean min max ZT0-3 34.05 34.05 34.05 ZT4-7 27.1 27.1 27.1 ZT8-11 15.75 15.75 15.75 ZT12-15 24.0 24.0 24.0 ZT16-19 21.1 21.1 21.1 ZT20-23 6.7 6.7 6.7