condition mean min max ZT0-3 17.7 17.7 17.7 ZT4-7 4.3 4.3 4.3 ZT8-11 25.6 25.6 25.6 ZT12-15 38.75 38.75 38.75 ZT16-19 26.6 26.6 26.6 ZT20-23 28.5 28.5 28.5