condition mean min max ZT0-3 13.55 13.55 13.55 ZT4-7 3.0 3.0 3.0 ZT8-11 4.5 4.5 4.5 ZT12-15 10.1 10.1 10.1 ZT16-19 23.75 23.75 23.75 ZT20-23 3.7 3.7 3.7