condition mean min max ZT0-3 7.25 7.25 7.25 ZT4-7 5.9 5.9 5.9 ZT8-11 11.35 11.35 11.35 ZT12-15 24.85 24.85 24.85 ZT16-19 5.75 5.75 5.75 ZT20-23 10.55 10.55 10.55