condition mean min max ZT0-3 4.3 4.3 4.3 ZT4-7 10.8 10.8 10.8 ZT8-11 38.05 38.05 38.05 ZT12-15 20.55 20.55 20.55 ZT16-19 21.25 21.25 21.25 ZT20-23 26.4 26.4 26.4