condition mean min max ZT0-3 4.0 4.0 4.0 ZT4-7 3.8 3.8 3.8 ZT8-11 18.75 18.75 18.75 ZT12-15 11.55 11.55 11.55 ZT16-19 2.05 2.05 2.05 ZT20-23 3.2 3.2 3.2