condition mean min max ZT0-3 5.25 5.25 5.25 ZT4-7 6.9 6.9 6.9 ZT8-11 21.75 21.75 21.75 ZT12-15 12.15 12.15 12.15 ZT16-19 4.25 4.25 4.25 ZT20-23 13.05 13.05 13.05