condition mean min max ZT0-3 25.5 25.5 25.5 ZT4-7 5.8 5.8 5.8 ZT8-11 13.35 13.35 13.35 ZT12-15 18.45 18.45 18.45 ZT16-19 33.0 33.0 33.0 ZT20-23 20.2 20.2 20.2