condition mean min max ZT0-3 30.75 30.75 30.75 ZT4-7 25.3 25.3 25.3 ZT8-11 33.8 33.8 33.8 ZT12-15 18.75 18.75 18.75 ZT16-19 22.0 22.0 22.0 ZT20-23 32.7 32.7 32.7