condition mean min max ZT0-3 3.95 3.95 3.95 ZT4-7 3.1 3.1 3.1 ZT8-11 19.5 19.5 19.5 ZT12-15 12.9 12.9 12.9 ZT16-19 23.25 23.25 23.25 ZT20-23 4.45 4.45 4.45