condition mean min max ZT0-3 4.05 4.05 4.05 ZT4-7 6.3 6.3 6.3 ZT8-11 27.1 27.1 27.1 ZT12-15 12.55 12.55 12.55 ZT16-19 11.75 11.75 11.75 ZT20-23 3.15 3.15 3.15